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source: GTP/trunk/Lib/Vis/Preprocessing/src/ViewCellBsp.cpp @ 1002

Revision 1002, 81.4 KB checked in by mattausch, 18 years ago (diff)
debug run: fixing memory holes

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	namespace GtpVisibilityPreprocessor {
18
19
20	//-- static members
21
22	int BspNode::sMailId = 1;
23
24	/** Evaluates split plane classification with respect to the plane's
25	contribution for a minimum number splits in the tree.
26	*/
27	const float BspTree::sLeastPolySplitsTable[] = {0, 0, 1, 0};
28	/** Evaluates split plane classification with respect to the plane's
29	contribution for a balanced tree.
30	*/
31	const float BspTree::sBalancedPolysTable[] = {1, -1, 0, 0};
32
33	/** Evaluates split plane classification with respect to the plane's
34	contribution for a minimum number of ray splits.
35	*/
36	const float BspTree::sLeastRaySplitsTable[] = {0, 0, 1, 1, 0};
37	/** Evaluates split plane classification with respect to the plane's
38	contribution for balanced rays.
39	*/
40	const float BspTree::sBalancedRaysTable[] = {1, -1, 0, 0, 0};
41
42	int BspTree::sFrontId = 0;
43	int BspTree::sBackId = 0;
44	int BspTree::sFrontAndBackId = 0;
45
46
47	/******************************************************************/
48	/* class BspNode implementation */
49	/******************************************************************/
50
51
52	BspNode::BspNode():
53	mParent(NULL), mTreeValid(true), mTimeStamp(0)
54	{}
55
56
57	BspNode::BspNode(BspInterior *parent):
58	mParent(parent), mTreeValid(true)
59	{}
60
61
62	bool BspNode::IsRoot() const
63	{
64	return mParent == NULL;
65	}
66
67
68	BspInterior *BspNode::GetParent()
69	{
70	return mParent;
71	}
72
73
74	void BspNode::SetParent(BspInterior *parent)
75	{
76	mParent = parent;
77	}
78
79
80	bool BspNode::IsSibling(BspNode *n) const
81	{
82	return ((this != n) && mParent &&
83	(mParent->GetFront() == n) \|\| (mParent->GetBack() == n));
84	}
85
86
87	int BspNode::GetDepth() const
88	{
89	int depth = 0;
90	BspNode *p = mParent;
91
92	while (p)
93	{
94	p = p->mParent;
95	++ depth;
96	}
97
98	return depth;
99	}
100
101
102	bool BspNode::TreeValid() const
103	{
104	return mTreeValid;
105	}
106
107
108	void BspNode::SetTreeValid(const bool v)
109	{
110	mTreeValid = v;
111	}
112
113
114	/****************************************************************/
115	/* class BspInterior implementation */
116	/****************************************************************/
117
118
119	BspInterior::BspInterior(const Plane3 &plane):
120	mPlane(plane), mFront(NULL), mBack(NULL)
121	{}
122
123	BspInterior::~BspInterior()
124	{
125	DEL_PTR(mFront);
126	DEL_PTR(mBack);
127	}
128
129	bool BspInterior::IsLeaf() const
130	{
131	return false;
132	}
133
134	BspNode *BspInterior::GetBack()
135	{
136	return mBack;
137	}
138
139	BspNode *BspInterior::GetFront()
140	{
141	return mFront;
142	}
143
144	Plane3 BspInterior::GetPlane() const
145	{
146	return mPlane;
147	}
148
149	void BspInterior::ReplaceChildLink(BspNode oldChild, BspNode newChild)
150	{
151	if (mBack == oldChild)
152	mBack = newChild;
153	else
154	mFront = newChild;
155	}
156
157	void BspInterior::SetupChildLinks(BspNode b, BspNode f)
158	{
159	mBack = b;
160	mFront = f;
161	}
162
163
164	/****************************************************************/
165	/* class BspLeaf implementation */
166	/****************************************************************/
167
168
169	BspLeaf::BspLeaf(): mViewCell(NULL), mPvs(NULL)
170	{
171	}
172
173
174	BspLeaf::~BspLeaf()
175	{
176	DEL_PTR(mPvs);
177	}
178
179
180	BspLeaf::BspLeaf(ViewCellLeaf *viewCell):
181	mViewCell(viewCell)
182	{
183	}
184
185
186	BspLeaf::BspLeaf(BspInterior *parent):
187	BspNode(parent), mViewCell(NULL), mPvs(NULL)
188	{}
189
190
191
192	BspLeaf::BspLeaf(BspInterior parent, ViewCellLeaf viewCell):
193	BspNode(parent), mViewCell(viewCell), mPvs(NULL)
194	{
195	}
196
197	ViewCellLeaf *BspLeaf::GetViewCell() const
198	{
199	return mViewCell;
200	}
201
202	void BspLeaf::SetViewCell(ViewCellLeaf *viewCell)
203	{
204	mViewCell = viewCell;
205	}
206
207
208	bool BspLeaf::IsLeaf() const
209	{
210	return true;
211	}
212
213
214	/*********************************************************************/
215	/* class BspTree implementation */
216	/*********************************************************************/
217
218	BspTree::BspTree():
219	mRoot(NULL),
220	mUseAreaForPvs(false),
221	mGenerateViewCells(true),
222	mTimeStamp(1)
223	{
224	Randomize(); // initialise random generator for heuristics
225
226	mOutOfBoundsCell = GetOrCreateOutOfBoundsCell();
227
228	//-- termination criteria for autopartition
229	environment->GetIntValue("BspTree.Termination.maxDepth", mTermMaxDepth);
230	environment->GetIntValue("BspTree.Termination.minPvs", mTermMinPvs);
231	environment->GetIntValue("BspTree.Termination.minPolygons", mTermMinPolys);
232	environment->GetIntValue("BspTree.Termination.minRays", mTermMinRays);
233	environment->GetFloatValue("BspTree.Termination.minProbability", mTermMinProbability);
234	environment->GetFloatValue("BspTree.Termination.maxRayContribution", mTermMaxRayContribution);
235	environment->GetFloatValue("BspTree.Termination.minAccRayLenght", mTermMinAccRayLength);
236
237	//-- factors for bsp tree split plane heuristics
238	environment->GetFloatValue("BspTree.Factor.verticalSplits", mVerticalSplitsFactor);
239	environment->GetFloatValue("BspTree.Factor.largestPolyArea", mLargestPolyAreaFactor);
240	environment->GetFloatValue("BspTree.Factor.blockedRays", mBlockedRaysFactor);
241	environment->GetFloatValue("BspTree.Factor.leastRaySplits", mLeastRaySplitsFactor);
242	environment->GetFloatValue("BspTree.Factor.balancedRays", mBalancedRaysFactor);
243	environment->GetFloatValue("BspTree.Factor.pvs", mPvsFactor);
244	environment->GetFloatValue("BspTree.Factor.leastSplits" , mLeastSplitsFactor);
245	environment->GetFloatValue("BspTree.Factor.balancedPolys", mBalancedPolysFactor);
246	environment->GetFloatValue("BspTree.Factor.balancedViewCells", mBalancedViewCellsFactor);
247	environment->GetFloatValue("BspTree.Termination.ct_div_ci", mCtDivCi);
248
249	//-- termination criteria for axis aligned split
250	environment->GetFloatValue("BspTree.Termination.AxisAligned.ct_div_ci", mAxisAlignedCtDivCi);
251	environment->GetFloatValue("BspTree.Termination.maxCostRatio", mMaxCostRatio);
252	environment->GetIntValue("BspTree.Termination.AxisAligned.minPolys",
253	mTermMinPolysForAxisAligned);
254	environment->GetIntValue("BspTree.Termination.AxisAligned.minRays",
255	mTermMinRaysForAxisAligned);
256	environment->GetIntValue("BspTree.Termination.AxisAligned.minObjects",
257	mTermMinObjectsForAxisAligned);
258	//-- partition criteria
259	environment->GetIntValue("BspTree.maxPolyCandidates", mMaxPolyCandidates);
260	environment->GetIntValue("BspTree.maxRayCandidates", mMaxRayCandidates);
261	environment->GetIntValue("BspTree.splitPlaneStrategy", mSplitPlaneStrategy);
262	environment->GetFloatValue("BspTree.AxisAligned.splitBorder", mSplitBorder);
263	environment->GetIntValue("BspTree.maxTests", mMaxTests);
264	environment->GetIntValue("BspTree.Termination.maxViewCells", mMaxViewCells);
265
266	environment->GetFloatValue("BspTree.Construction.epsilon", mEpsilon);
267
268	char subdivisionStatsLog[100];
269	environment->GetStringValue("BspTree.subdivisionStats", subdivisionStatsLog);
270	mSubdivisionStats.open(subdivisionStatsLog);
271
272	Debug << "BSP max depth: " << mTermMaxDepth << endl;
273	Debug << "BSP min PVS: " << mTermMinPvs << endl;
274	Debug << "BSP min probability: " << mTermMinProbability << endl;
275	Debug << "BSP max polys: " << mTermMinPolys << endl;
276	Debug << "BSP max rays: " << mTermMinRays << endl;
277	Debug << "BSP max polygon candidates: " << mMaxPolyCandidates << endl;
278	Debug << "BSP max plane candidates: " << mMaxRayCandidates << endl;
279
280	Debug << "Split plane strategy: ";
281	if (mSplitPlaneStrategy & RANDOM_POLYGON)
282	Debug << "random polygon ";
283	if (mSplitPlaneStrategy & AXIS_ALIGNED)
284	Debug << "axis aligned ";
285	if (mSplitPlaneStrategy & LEAST_SPLITS)
286	Debug << "least splits ";
287	if (mSplitPlaneStrategy & BALANCED_POLYS)
288	Debug << "balanced polygons ";
289	if (mSplitPlaneStrategy & BALANCED_VIEW_CELLS)
290	Debug << "balanced view cells ";
291	if (mSplitPlaneStrategy & LARGEST_POLY_AREA)
292	Debug << "largest polygon area ";
293	if (mSplitPlaneStrategy & VERTICAL_AXIS)
294	Debug << "vertical axis ";
295	if (mSplitPlaneStrategy & BLOCKED_RAYS)
296	Debug << "blocked rays ";
297	if (mSplitPlaneStrategy & LEAST_RAY_SPLITS)
298	Debug << "least ray splits ";
299	if (mSplitPlaneStrategy & BALANCED_RAYS)
300	Debug << "balanced rays ";
301	if (mSplitPlaneStrategy & PVS)
302	Debug << "pvs";
303
304	Debug << endl;
305	}
306
307
308	const BspTreeStatistics &BspTree::GetStatistics() const
309	{
310	return mStat;
311	}
312
313
314	int BspTree::SplitPolygons(const Plane3 &plane,
315	PolygonContainer &polys,
316	PolygonContainer &frontPolys,
317	PolygonContainer &backPolys,
318	PolygonContainer &coincident) const
319	{
320	int splits = 0;
321
322	#ifdef _Debug
323	Debug << "splitting polygons of node " << this << " with plane " << mPlane << endl;
324	#endif
325
326	PolygonContainer::const_iterator it, it_end = polys.end();
327
328	for (it = polys.begin(); it != polys.end(); ++ it)
329	{
330	Polygon3 poly = it;
331
332	//-- classify polygon
333	const int cf = poly->ClassifyPlane(plane, mEpsilon);
334
335	switch (cf)
336	{
337	case Polygon3::COINCIDENT:
338	coincident.push_back(poly);
339	break;
340	case Polygon3::FRONT_SIDE:
341	frontPolys.push_back(poly);
342	break;
343	case Polygon3::BACK_SIDE:
344	backPolys.push_back(poly);
345	break;
346	case Polygon3::SPLIT:
347	{
348	Polygon3 *front_piece = new Polygon3(poly->mParent);
349	Polygon3 *back_piece = new Polygon3(poly->mParent);
350
351	//-- split polygon into front and back part
352	poly->Split(plane,
353	*front_piece,
354	*back_piece,
355	mEpsilon);
356
357	++ splits; // increase number of splits
358
359	//-- inherit rays from parent polygon for blocked ray criterium
360	poly->InheritRays(front_piece, back_piece);
361
362	// check if polygons still valid
363	if (front_piece->Valid(mEpsilon))
364	frontPolys.push_back(front_piece);
365	else
366	DEL_PTR(front_piece);
367
368	if (back_piece->Valid(mEpsilon))
369	backPolys.push_back(back_piece);
370	else
371	DEL_PTR(back_piece);
372
373	#ifdef _DEBUG
374	Debug << "split " << poly << endl << front_piece << endl << *back_piece << endl;
375	#endif
376	DEL_PTR(poly);
377	}
378	break;
379	default:
380	Debug << "SHOULD NEVER COME HERE\n";
381	break;
382	}
383	}
384
385	return splits;
386	}
387
388
389	void BspTreeStatistics::Print(ostream &app) const
390	{
391	app << "===== BspTree statistics ===============\n";
392
393	app << setprecision(4);
394
395	app << "#N_CTIME ( Construction time [s] )\n" << Time() << " \n";
396
397	app << "#N_NODES ( Number of nodes )\n" << nodes << "\n";
398
399	app << "#N_INTERIORS ( Number of interior nodes )\n" << Interior() << "\n";
400
401	app << "#N_LEAVES ( Number of leaves )\n" << Leaves() << "\n";
402
403	app << "#N_POLYSPLITS ( Number of polygon splits )\n" << polySplits << "\n";
404
405	app << "#AXIS_ALIGNED_SPLITS (number of axis aligned splits)\n" << splits[0] + splits[1] + splits[2] << endl;
406
407	app << "#N_SPLITS ( Number of splits in axes x y z)\n";
408
409	for (int i = 0; i < 3; ++ i)
410	app << splits[i] << " ";
411	app << endl;
412
413	app << "#N_PMAXDEPTHLEAVES ( Percentage of leaves at maximum depth )\n"
414	<< maxDepthNodes * 100 / (double)Leaves() << endl;
415
416	app << "#N_PMINPVSLEAVES ( Percentage of leaves with mininimal PVS )\n"
417	<< minPvsNodes * 100 / (double)Leaves() << endl;
418
419	app << "#N_PMINRAYSLEAVES ( Percentage of leaves with minimal number of rays)\n"
420	<< minRaysNodes * 100 / (double)Leaves() << endl;
421
422	app << "#N_MAXCOSTNODES ( Percentage of leaves with terminated because of max cost ratio )\n"
423	<< maxCostNodes * 100 / (double)Leaves() << endl;
424
425	app << "#N_PMINPROBABILITYLEAVES ( Percentage of leaves with mininum probability )\n"
426	<< minProbabilityNodes * 100 / (double)Leaves() << endl;
427
428	app << "#N_PMAXRAYCONTRIBLEAVES ( Percentage of leaves with maximal ray contribution )\n"
429	<< maxRayContribNodes * 100 / (double)Leaves() << endl;
430
431	app << "#N_PMAXDEPTH ( Maximal reached depth )\n" << maxDepth << endl;
432
433	app << "#N_PMINDEPTH ( Minimal reached depth )\n" << minDepth << endl;
434
435	app << "#AVGDEPTH ( average depth )\n" << AvgDepth() << endl;
436
437	app << "#N_INPUTPOLYGONS (number of input polygons )\n" << polys << endl;
438
439	app << "#N_INVALIDLEAVES (number of invalid leaves )\n" << invalidLeaves << endl;
440
441	app << "#N_RAYS (number of rays / leaf)\n" << AvgRays() << endl;
442	//app << "#N_PVS: " << pvs << endl;
443
444	app << "#N_ROUTPUT_INPUT_POLYGONS ( ratio polygons after subdivision / input polygons )\n" <<
445	(polys + polySplits) / (double)polys << endl;
446
447	app << "===== END OF BspTree statistics ==========\n";
448	}
449
450
451	BspTree::~BspTree()
452	{
453	DEL_PTR(mRoot);
454
455	// TODO must be deleted if used!!
456	//if (mGenerateViewCells) DEL_PTR(mOutOfBoundsCell);
457	}
458
459	BspViewCell *BspTree::GetOutOfBoundsCell()
460	{
461	return mOutOfBoundsCell;
462	}
463
464
465	BspNode *BspTree::GetRoot() const
466	{
467	return mRoot;
468	}
469
470
471	BspViewCell *BspTree::GetOrCreateOutOfBoundsCell()
472	{
473	if (!mOutOfBoundsCell)
474	{
475	mOutOfBoundsCell = new BspViewCell();
476	mOutOfBoundsCell->SetId(-1);
477	mOutOfBoundsCell->SetValid(false);
478	}
479
480	return mOutOfBoundsCell;
481	}
482
483
484	void BspTree::InsertViewCell(ViewCellLeaf *viewCell)
485	{
486	PolygonContainer *polys = new PolygonContainer();
487
488	// don't generate new view cell, insert this one
489	mGenerateViewCells = false;
490	// extract polygons that guide the split process
491	mStat.polys += AddMeshToPolygons(viewCell->GetMesh(), *polys, viewCell);
492	mBox.Include(viewCell->GetBox()); // add to BSP aabb
493
494	InsertPolygons(polys);
495	}
496
497
498	void BspTree::InsertPolygons(PolygonContainer *polys)
499	{
500	BspTraversalStack tStack;
501
502	// traverse existing tree or create new tree
503	if (!mRoot)
504	mRoot = new BspLeaf();
505
506	tStack.push(BspTraversalData(mRoot,
507	polys,
508	0,
509	mOutOfBoundsCell,
510	new BoundedRayContainer(),
511	0,
512	mUseAreaForPvs ? mBox.SurfaceArea() : mBox.GetVolume(),
513	new BspNodeGeometry()));
514
515	while (!tStack.empty())
516	{
517	// filter polygons donw the tree
518	BspTraversalData tData = tStack.top();
519	tStack.pop();
520
521	if (!tData.mNode->IsLeaf())
522	{
523	BspInterior interior = dynamic_cast<BspInterior >(tData.mNode);
524
525	//-- filter view cell polygons down the tree until a leaf is reached
526	if (!tData.mPolygons->empty())
527	{
528	PolygonContainer *frontPolys = new PolygonContainer();
529	PolygonContainer *backPolys = new PolygonContainer();
530	PolygonContainer coincident;
531
532	int splits = 0;
533
534	// split viewcell polygons with respect to split plane
535	splits += SplitPolygons(interior->GetPlane(),
536	*tData.mPolygons,
537	*frontPolys,
538	*backPolys,
539	coincident);
540
541	// extract view cells associated with the split polygons
542	ViewCellLeaf *frontViewCell = GetOrCreateOutOfBoundsCell();
543	ViewCellLeaf *backViewCell = GetOrCreateOutOfBoundsCell();
544
545	BspTraversalData frontData(interior->GetFront(),
546	frontPolys,
547	tData.mDepth + 1,
548	mOutOfBoundsCell,
549	tData.mRays,
550	tData.mPvs,
551	mUseAreaForPvs ? mBox.SurfaceArea() : mBox.GetVolume(),
552	new BspNodeGeometry());
553
554	BspTraversalData backData(interior->GetBack(),
555	backPolys,
556	tData.mDepth + 1,
557	mOutOfBoundsCell,
558	tData.mRays,
559	tData.mPvs,
560	mUseAreaForPvs ? mBox.SurfaceArea() : mBox.GetVolume(),
561	new BspNodeGeometry());
562
563	if (!mGenerateViewCells)
564	{
565	ExtractViewCells(frontData,
566	backData,
567	coincident,
568	interior->mPlane);
569	}
570
571	// don't need coincident polygons anymore
572	CLEAR_CONTAINER(coincident);
573
574	mStat.polySplits += splits;
575
576	// push the children on the stack
577	tStack.push(frontData);
578	tStack.push(backData);
579	}
580
581	// cleanup
582	DEL_PTR(tData.mPolygons);
583	DEL_PTR(tData.mRays);
584	}
585	else
586	{
587	// reached leaf => subdivide current viewcell
588	BspNode *subRoot = Subdivide(tStack, tData);
589	}
590	}
591	}
592
593
594	int BspTree::AddMeshToPolygons(Mesh *mesh,
595	PolygonContainer &polys,
596	MeshInstance *parent)
597	{
598	FaceContainer::const_iterator fi, fi_end = mesh->mFaces.end();
599
600	// copy the face data to polygons
601	for (fi = mesh->mFaces.begin(); fi != fi_end; ++ fi)
602	{
603	Polygon3 poly = new Polygon3((fi), mesh);
604
605	if (poly->Valid(mEpsilon))
606	{
607	poly->mParent = parent; // set parent intersectable
608	polys.push_back(poly);
609	}
610	else
611	DEL_PTR(poly);
612	}
613	return (int)mesh->mFaces.size();
614	}
615
616
617	int BspTree::AddToPolygonSoup(const ViewCellContainer &viewCells,
618	PolygonContainer &polys,
619	int maxObjects)
620	{
621	int limit = (maxObjects > 0) ?
622	Min((int)viewCells.size(), maxObjects) : (int)viewCells.size();
623
624	int polysSize = 0;
625
626	for (int i = 0; i < limit; ++ i)
627	{
628	if (viewCells[i]->GetMesh()) // copy the mesh data to polygons
629	{
630	mBox.Include(viewCells[i]->GetBox()); // add to BSP tree aabb
631	polysSize += AddMeshToPolygons(viewCells[i]->GetMesh(), polys, viewCells[i]);
632	}
633	}
634
635	return polysSize;
636	}
637
638
639	int BspTree::AddToPolygonSoup(const ObjectContainer &objects,
640	PolygonContainer &polys,
641	int maxObjects,
642	bool addToBbox)
643	{
644	int limit = (maxObjects > 0) ?
645	Min((int)objects.size(), maxObjects) : (int)objects.size();
646
647	for (int i = 0; i < limit; ++i)
648	{
649	Intersectable *object = objects[i];
650
651	Mesh *mesh = NULL;
652
653	switch (object->Type()) // extract the meshes
654	{
655	case Intersectable::MESH_INSTANCE:
656	mesh = dynamic_cast<MeshInstance *>(object)->GetMesh();
657	break;
658	case Intersectable::VIEW_CELL:
659	mesh = dynamic_cast<ViewCell *>(object)->GetMesh();
660	break;
661	case Intersectable::TRANSFORMED_MESH_INSTANCE:
662	{
663	TransformedMeshInstance mi = dynamic_cast<TransformedMeshInstance >(object);
664
665	if (!mi->GetMesh())
666	break;
667	mesh = new Mesh();
668	mi->GetTransformedMesh(*mesh);
669
670	break;
671	}
672	default:
673	Debug << "intersectable type not supported" << endl;
674	break;
675	}
676
677	if (mesh) // copy the mesh data to polygons
678	{
679	if (addToBbox)
680	mBox.Include(object->GetBox()); // add to BSP tree aabb
681
682	AddMeshToPolygons(mesh, polys, mOutOfBoundsCell);
683
684	// cleanup
685	if (object->Type() == Intersectable::TRANSFORMED_MESH_INSTANCE)
686	DEL_PTR(mesh);
687	}
688	}
689
690	return (int)polys.size();
691	}
692
693
694	void BspTree::Construct(const ViewCellContainer &viewCells)
695	{
696	mStat.nodes = 1;
697	mBox.Initialize(); // initialise bsp tree bounding box
698
699	// copy view cell meshes into one big polygon soup
700	PolygonContainer *polys = new PolygonContainer();
701	mStat.polys = AddToPolygonSoup(viewCells, *polys);
702
703	// view cells are given
704	mGenerateViewCells = false;
705	// construct tree from the view cell polygons
706	Construct(polys, new BoundedRayContainer());
707	}
708
709
710	void BspTree::Construct(const ObjectContainer &objects)
711	{
712	mStat.nodes = 1;
713	mBox.Initialize(); // initialise bsp tree bounding box
714
715	PolygonContainer *polys = new PolygonContainer();
716
717	mGenerateViewCells = true;
718	// copy mesh instance polygons into one big polygon soup
719	mStat.polys = AddToPolygonSoup(objects, *polys);
720
721	// construct tree from polygon soup
722	Construct(polys, new BoundedRayContainer());
723	}
724
725
726	void BspTree::PreprocessPolygons(PolygonContainer &polys)
727	{
728	// preprocess: throw out polygons coincident to the view space box (not needed)
729	PolygonContainer boxPolys;
730	mBox.ExtractPolys(boxPolys);
731	vector<Plane3> boxPlanes;
732
733	PolygonContainer::iterator pit, pit_end = boxPolys.end();
734
735	// extract planes of box
736	// TODO: can be done more elegantly than first extracting polygons
737	// and take their planes
738	for (pit = boxPolys.begin(); pit != pit_end; ++ pit)
739	{
740	boxPlanes.push_back((*pit)->GetSupportingPlane());
741	}
742
743	pit_end = polys.end();
744
745	for (pit = polys.begin(); pit != pit_end; ++ pit)
746	{
747	vector<Plane3>::const_iterator bit, bit_end = boxPlanes.end();
748
749	for (bit = boxPlanes.begin(); (bit != bit_end) && (*pit); ++ bit)
750	{
751	const int cf = (pit)->ClassifyPlane(bit, mEpsilon);
752
753	if (cf == Polygon3::COINCIDENT)
754	{
755	DEL_PTR(*pit);
756	//Debug << "coincident!!" << endl;
757	}
758	}
759	}
760
761	// remove deleted entries
762	for (int i = 0; i < (int)polys.size(); ++ i)
763	{
764	while (!polys[i] && (i < (int)polys.size()))
765	{
766	swap(polys[i], polys.back());
767	polys.pop_back();
768	}
769	}
770
771	CLEAR_CONTAINER(boxPolys);
772	}
773
774
775
776	void BspTree::Construct(const RayContainer &sampleRays,
777	AxisAlignedBox3 *forcedBoundingBox)
778	{
779	mStat.nodes = 1;
780	mBox.Initialize(); // initialise BSP tree bounding box
781
782	if (forcedBoundingBox)
783	mBox = *forcedBoundingBox;
784
785	PolygonContainer *polys = new PolygonContainer();
786	BoundedRayContainer *rays = new BoundedRayContainer();
787
788	RayContainer::const_iterator rit, rit_end = sampleRays.end();
789
790	// generate view cells
791	mGenerateViewCells = true;
792
793	long startTime = GetTime();
794
795	Debug << "** Extracting polygons from rays **\n";
796
797	std::map<Face , Polygon3 > facePolyMap;
798
799	//-- extract polygons intersected by the rays
800	for (rit = sampleRays.begin(); rit != rit_end; ++ rit)
801	{
802	Ray ray = rit;
803
804	// get ray-face intersection. Store polygon representing the rays together
805	// with rays intersecting the face.
806	if (!ray->intersections.empty())
807	{
808	MeshInstance obj = dynamic_cast<MeshInstance >(ray->intersections[0].mObject);
809
810	Mesh *mesh;
811	if (obj->Type() == Intersectable::TRANSFORMED_MESH_INSTANCE)
812	{
813	TransformedMeshInstance *tmobj =
814	dynamic_cast<TransformedMeshInstance *>(obj);
815
816	mesh = new Mesh();
817	tmobj->GetTransformedMesh(*mesh);
818	}
819	else // MeshInstance
820	{
821	mesh = obj->GetMesh();
822	}
823
824	Face *face = mesh->mFaces[ray->intersections[0].mFace];
825	std::map<Face , Polygon3 >::iterator it = facePolyMap.find(face);
826
827	if (it != facePolyMap.end())
828	{
829	//store rays if needed for heuristics
830	if (mSplitPlaneStrategy & BLOCKED_RAYS)
831	(*it).second->mPiercingRays.push_back(ray);
832	}
833	else
834	{
835	//store rays if needed for heuristics
836	Polygon3 *poly = new Polygon3(face, mesh);
837	poly->mParent = obj;
838	polys->push_back(poly);
839
840	if (mSplitPlaneStrategy & BLOCKED_RAYS)
841	poly->mPiercingRays.push_back(ray);
842
843	facePolyMap[face] = poly;
844	}
845
846	// cleanup
847	if (obj->Type() == Intersectable::TRANSFORMED_MESH_INSTANCE)
848	DEL_PTR(mesh);
849	}
850	}
851
852	facePolyMap.clear();
853
854	// compute bounding box
855	if (!forcedBoundingBox)
856	mBox.Include(*polys);
857
858	//-- store rays
859	for (rit = sampleRays.begin(); rit != rit_end; ++ rit)
860	{
861	Ray ray = rit;
862	ray->SetId(-1); // reset id
863
864	float minT, maxT;
865	if (mBox.GetRaySegment(*ray, minT, maxT))
866	rays->push_back(new BoundedRay(ray, minT, maxT));
867	}
868
869	// throw out bad polygons
870	PreprocessPolygons(*polys);
871
872	mStat.polys = (int)polys->size();
873
874	Debug << "** Finished polygon extraction **" << endl;
875	Debug << (int)polys->size() << " polys extracted from " << (int)sampleRays.size() << " rays" << endl;
876	Debug << "extraction time: " << TimeDiff(startTime, GetTime())*1e-3 << "s" << endl;
877
878	Construct(polys, rays);
879	}
880
881
882	void BspTree::Construct(const ObjectContainer &objects,
883	const RayContainer &sampleRays,
884	AxisAlignedBox3 *forcedBoundingBox)
885	{
886	mStat.nodes = 1;
887	mBox.Initialize(); // initialise BSP tree bounding box
888
889	if (forcedBoundingBox)
890	mBox = *forcedBoundingBox;
891
892	BoundedRayContainer *rays = new BoundedRayContainer();
893	PolygonContainer *polys = new PolygonContainer();
894
895	mGenerateViewCells = true;
896
897	// copy mesh instance polygons into one big polygon soup
898	mStat.polys = AddToPolygonSoup(objects, *polys, 0, !forcedBoundingBox);
899
900
901	RayContainer::const_iterator rit, rit_end = sampleRays.end();
902
903	//-- store rays
904	for (rit = sampleRays.begin(); rit != rit_end; ++ rit)
905	{
906	Ray ray = rit;
907	ray->SetId(-1); // reset id
908
909	float minT, maxT;
910	if (mBox.GetRaySegment(*ray, minT, maxT))
911	rays->push_back(new BoundedRay(ray, minT, maxT));
912	}
913
914	PreprocessPolygons(*polys);
915	Debug << "tree has " << (int)polys->size() << " polys, " << (int)sampleRays.size() << " rays" << endl;
916	Construct(polys, rays);
917	}
918
919
920	void BspTree::Construct(PolygonContainer polys, BoundedRayContainer rays)
921	{
922	BspTraversalStack tStack;
923
924	mRoot = new BspLeaf();
925
926	// constrruct root node geometry
927	BspNodeGeometry *geom = new BspNodeGeometry();
928	ConstructGeometry(mRoot, *geom);
929
930	BspTraversalData tData(mRoot,
931	polys,
932	0,
933	GetOrCreateOutOfBoundsCell(),
934	rays,
935	ComputePvsSize(*rays),
936	mUseAreaForPvs ? geom->GetArea() : geom->GetVolume(),
937	geom);
938
939	mTotalCost = tData.mPvs * tData.mProbability / mBox.GetVolume();
940	mTotalPvsSize = tData.mPvs;
941
942	mSubdivisionStats
943	<< "#ViewCells\n1\n" << endl
944	<< "#RenderCostDecrease\n0\n" << endl
945	<< "#TotalRenderCost\n" << mTotalCost << endl
946	<< "#AvgRenderCost\n" << mTotalPvsSize << endl;
947
948	tStack.push(tData);
949
950	// used for intermediate time measurements and progress
951	long interTime = GetTime();
952	int nleaves = 500;
953
954	mStat.Start();
955	cout << "Constructing bsp tree ...\n";
956	long startTime = GetTime();
957	while (!tStack.empty())
958	{
959	tData = tStack.top();
960
961	tStack.pop();
962
963	// subdivide leaf node
964	BspNode *r = Subdivide(tStack, tData);
965
966	if (r == mRoot)
967	Debug << "BSP tree construction time spent at root: "
968	<< TimeDiff(startTime, GetTime())*1e-3 << " secs" << endl;
969
970	if (mStat.Leaves() >= nleaves)
971	{
972	nleaves += 500;
973
974	cout << "leaves=" << mStat.Leaves() << endl;
975	Debug << "needed "
976	<< TimeDiff(interTime, GetTime())*1e-3
977	<< " secs to create 500 leaves" << endl;
978	interTime = GetTime();
979	}
980	}
981
982	cout << "finished\n";
983
984	mStat.Stop();
985	}
986
987
988	bool BspTree::TerminationCriteriaMet(const BspTraversalData &data) const
989	{
990	return
991	(((int)data.mPolygons->size() <= mTermMinPolys) \|\|
992	((int)data.mRays->size() <= mTermMinRays) \|\|
993	(data.mPvs <= mTermMinPvs) \|\|
994	(data.mProbability <= mTermMinProbability) \|\|
995	(data.mDepth >= mTermMaxDepth) \|\|
996	(mStat.Leaves() >= mMaxViewCells) \|\|
997	(data.GetAvgRayContribution() > mTermMaxRayContribution));
998	}
999
1000
1001	BspNode *BspTree::Subdivide(BspTraversalStack &tStack, BspTraversalData &tData)
1002	{
1003	//-- terminate traversal
1004	if (TerminationCriteriaMet(tData))
1005	{
1006	BspLeaf leaf = dynamic_cast<BspLeaf >(tData.mNode);
1007
1008	BspViewCell *viewCell;
1009
1010	// generate new view cell for each leaf
1011	if (mGenerateViewCells)
1012	viewCell = new BspViewCell();
1013	else
1014	// add view cell to leaf
1015	viewCell = dynamic_cast<BspViewCell *>(tData.mViewCell);
1016
1017	leaf->SetViewCell(viewCell);
1018	viewCell->mLeaf = leaf;
1019
1020	//float probability = max(0.0f, tData.mProbability);
1021	float probability = tData.mProbability;
1022
1023	if (mUseAreaForPvs)
1024	viewCell->SetArea(probability);
1025	else
1026	viewCell->SetVolume(probability);
1027
1028	//-- add pvs
1029	if (viewCell != mOutOfBoundsCell)
1030	{
1031	int conSamp = 0, sampCon = 0;
1032	AddToPvs(leaf, *tData.mRays, conSamp, sampCon);
1033
1034	mStat.contributingSamples += conSamp;
1035	mStat.sampleContributions += sampCon;
1036	}
1037
1038	EvaluateLeafStats(tData);
1039
1040	//-- clean up
1041
1042	// discard polygons
1043	CLEAR_CONTAINER(*tData.mPolygons);
1044	// discard rays
1045	CLEAR_CONTAINER(*tData.mRays);
1046
1047	DEL_PTR(tData.mPolygons);
1048	DEL_PTR(tData.mRays);
1049	DEL_PTR(tData.mGeometry);
1050
1051	return leaf;
1052	}
1053
1054	//-- continue subdivision
1055	PolygonContainer coincident;
1056
1057	BspTraversalData tFrontData(NULL, new PolygonContainer(), tData.mDepth + 1, mOutOfBoundsCell,
1058	new BoundedRayContainer(), 0, 0, new BspNodeGeometry());
1059	BspTraversalData tBackData(NULL, new PolygonContainer(), tData.mDepth + 1, mOutOfBoundsCell,
1060	new BoundedRayContainer(), 0, 0, new BspNodeGeometry());
1061
1062
1063	// create new interior node and two leaf nodes
1064	BspInterior *interior =
1065	SubdivideNode(tData, tFrontData, tBackData, coincident);
1066
1067
1068	if (1)
1069	{
1070	int pvsData = tData.mPvs;
1071
1072	float cData = (float)pvsData * tData.mProbability;
1073	float cFront = (float)tFrontData.mPvs * tFrontData.mProbability;
1074	float cBack = (float)tBackData.mPvs * tBackData.mProbability;
1075
1076	float costDecr = (cFront + cBack - cData) / mBox.GetVolume();
1077
1078	mTotalCost += costDecr;
1079	mTotalPvsSize += tFrontData.mPvs + tBackData.mPvs - pvsData;
1080
1081	mSubdivisionStats
1082	<< "#ViewCells\n" << mStat.Leaves() << endl
1083	<< "#RenderCostDecrease\n" << -costDecr << endl
1084	<< "#TotalRenderCost\n" << mTotalCost << endl
1085	<< "#AvgRenderCost\n" << mTotalPvsSize / mStat.Leaves() << endl;
1086	}
1087
1088	// extract view cells from coincident polygons according to plane normal
1089	// only if front or back polygons are empty
1090	if (!mGenerateViewCells)
1091	{
1092	ExtractViewCells(tFrontData,
1093	tBackData,
1094	coincident,
1095	interior->mPlane);
1096	}
1097
1098	// don't need coincident polygons anymory
1099	CLEAR_CONTAINER(coincident);
1100
1101	// push the children on the stack
1102	tStack.push(tFrontData);
1103	tStack.push(tBackData);
1104
1105	// cleanup
1106	DEL_PTR(tData.mNode);
1107
1108	DEL_PTR(tData.mPolygons);
1109	DEL_PTR(tData.mRays);
1110	DEL_PTR(tData.mGeometry);
1111
1112	return interior;
1113	}
1114
1115
1116	void BspTree::ExtractViewCells(BspTraversalData &frontData,
1117	BspTraversalData &backData,
1118	const PolygonContainer &coincident,
1119	const Plane3 &splitPlane) const
1120	{
1121	// if not empty, tree is further subdivided => don't have to find view cell
1122	bool foundFront = !frontData.mPolygons->empty();
1123	bool foundBack = !frontData.mPolygons->empty();
1124
1125	PolygonContainer::const_iterator it =
1126	coincident.begin(), it_end = coincident.end();
1127
1128	//-- find first view cells in front and back leafs
1129	for (; !(foundFront && foundBack) && (it != it_end); ++ it)
1130	{
1131	if (DotProd((*it)->GetNormal(), splitPlane.mNormal) > 0)
1132	{
1133	backData.mViewCell = dynamic_cast<ViewCellLeaf >((it)->mParent);
1134	foundBack = true;
1135	}
1136	else
1137	{
1138	frontData.mViewCell = dynamic_cast<ViewCellLeaf >((it)->mParent);
1139	foundFront = true;
1140	}
1141	}
1142	}
1143
1144
1145	BspInterior *BspTree::SubdivideNode(BspTraversalData &tData,
1146	BspTraversalData &frontData,
1147	BspTraversalData &backData,
1148	PolygonContainer &coincident)
1149	{
1150	mStat.nodes += 2;
1151
1152	BspLeaf leaf = dynamic_cast<BspLeaf >(tData.mNode);
1153
1154
1155
1156	// select subdivision plane
1157	BspInterior *interior =
1158	new BspInterior(SelectPlane(leaf, tData));
1159
1160
1161	#ifdef _DEBUG
1162	Debug << interior << endl;
1163	#endif
1164
1165
1166	// subdivide rays into front and back rays
1167	SplitRays(interior->mPlane, tData.mRays, frontData.mRays, *backData.mRays);
1168
1169
1170
1171	// subdivide polygons with plane
1172	mStat.polySplits += SplitPolygons(interior->GetPlane(),
1173	*tData.mPolygons,
1174	*frontData.mPolygons,
1175	*backData.mPolygons,
1176	coincident);
1177
1178
1179
1180	// compute pvs
1181	frontData.mPvs = ComputePvsSize(*frontData.mRays);
1182	backData.mPvs = ComputePvsSize(*backData.mRays);
1183
1184	// split geometry and compute area
1185	if (1)
1186	{
1187	tData.mGeometry->SplitGeometry(*frontData.mGeometry,
1188	*backData.mGeometry,
1189	interior->mPlane,
1190	mBox,
1191	//0.000000000001);
1192	mEpsilon);
1193
1194
1195	if (mUseAreaForPvs)
1196	{
1197	frontData.mProbability = frontData.mGeometry->GetArea();
1198	backData.mProbability = backData.mGeometry->GetArea();
1199	}
1200	else
1201	{
1202	frontData.mProbability = frontData.mGeometry->GetVolume();
1203	backData.mProbability = tData.mProbability - frontData.mProbability;
1204	}
1205	}
1206
1207	//-- create front and back leaf
1208
1209	BspInterior *parent = leaf->GetParent();
1210
1211	// replace a link from node's parent
1212	if (!leaf->IsRoot())
1213	{
1214	parent->ReplaceChildLink(leaf, interior);
1215	interior->SetParent(parent);
1216	}
1217	else // new root
1218	{
1219	mRoot = interior;
1220	}
1221
1222	// and setup child links
1223	interior->SetupChildLinks(new BspLeaf(interior), new BspLeaf(interior));
1224
1225	frontData.mNode = interior->GetFront();
1226	backData.mNode = interior->GetBack();
1227
1228	interior->mTimeStamp = mTimeStamp ++;
1229
1230	//DEL_PTR(leaf);
1231	return interior;
1232	}
1233
1234
1235	void BspTree::SortSplitCandidates(const PolygonContainer &polys,
1236	const int axis,
1237	vector<SortableEntry> &splitCandidates) const
1238	{
1239	splitCandidates.clear();
1240
1241	int requestedSize = 2 * (int)polys.size();
1242	// creates a sorted split candidates array
1243	splitCandidates.reserve(requestedSize);
1244
1245	PolygonContainer::const_iterator it, it_end = polys.end();
1246
1247	AxisAlignedBox3 box;
1248
1249	// insert all queries
1250	for(it = polys.begin(); it != it_end; ++ it)
1251	{
1252	box.Initialize();
1253	box.Include((it));
1254
1255	splitCandidates.push_back(SortableEntry(SortableEntry::POLY_MIN, box.Min(axis), *it));
1256	splitCandidates.push_back(SortableEntry(SortableEntry::POLY_MAX, box.Max(axis), *it));
1257	}
1258
1259	stable_sort(splitCandidates.begin(), splitCandidates.end());
1260	}
1261
1262
1263	float BspTree::BestCostRatio(const PolygonContainer &polys,
1264	const AxisAlignedBox3 &box,
1265	const int axis,
1266	float &position,
1267	int &objectsBack,
1268	int &objectsFront) const
1269	{
1270	vector<SortableEntry> splitCandidates;
1271
1272	SortSplitCandidates(polys, axis, splitCandidates);
1273
1274	// go through the lists, count the number of objects left and right
1275	// and evaluate the following cost funcion:
1276	// C = ct_div_ci + (ol + or)/queries
1277
1278	int objectsLeft = 0, objectsRight = (int)polys.size();
1279
1280	float minBox = box.Min(axis);
1281	float maxBox = box.Max(axis);
1282	float boxArea = box.SurfaceArea();
1283
1284	float minBand = minBox + mSplitBorder * (maxBox - minBox);
1285	float maxBand = minBox + (1.0f - mSplitBorder) * (maxBox - minBox);
1286
1287	float minSum = 1e20f;
1288	vector<SortableEntry>::const_iterator ci, ci_end = splitCandidates.end();
1289
1290	for(ci = splitCandidates.begin(); ci != ci_end; ++ ci)
1291	{
1292	switch ((*ci).type)
1293	{
1294	case SortableEntry::POLY_MIN:
1295	++ objectsLeft;
1296	break;
1297	case SortableEntry::POLY_MAX:
1298	-- objectsRight;
1299	break;
1300	default:
1301	break;
1302	}
1303
1304	if ((ci).value > minBand && (ci).value < maxBand)
1305	{
1306	AxisAlignedBox3 lbox = box;
1307	AxisAlignedBox3 rbox = box;
1308	lbox.SetMax(axis, (*ci).value);
1309	rbox.SetMin(axis, (*ci).value);
1310
1311	const float sum = objectsLeft * lbox.SurfaceArea() +
1312	objectsRight * rbox.SurfaceArea();
1313
1314	if (sum < minSum)
1315	{
1316	minSum = sum;
1317	position = (*ci).value;
1318
1319	objectsBack = objectsLeft;
1320	objectsFront = objectsRight;
1321	}
1322	}
1323	}
1324
1325	const float oldCost = (float)polys.size();
1326	const float newCost = mAxisAlignedCtDivCi + minSum / boxArea;
1327	const float ratio = newCost / oldCost;
1328
1329
1330	#if 0
1331	Debug << "====================" << endl;
1332	Debug << "costRatio=" << ratio << " pos=" << position<<" t=" << (position - minBox)/(maxBox - minBox)
1333	<< "\t o=(" << objectsBack << "," << objectsFront << ")" << endl;
1334	#endif
1335	return ratio;
1336	}
1337
1338	bool BspTree::SelectAxisAlignedPlane(Plane3 &plane,
1339	const PolygonContainer &polys) const
1340	{
1341	AxisAlignedBox3 box;
1342	box.Initialize();
1343
1344	// create bounding box of region
1345	box.Include(polys);
1346
1347	int objectsBack = 0, objectsFront = 0;
1348	int axis = 0;
1349	float costRatio = MAX_FLOAT;
1350	Vector3 position;
1351
1352	//-- area subdivision
1353	for (int i = 0; i < 3; ++ i)
1354	{
1355	float p = 0;
1356	float r = BestCostRatio(polys, box, i, p, objectsBack, objectsFront);
1357
1358	if (r < costRatio)
1359	{
1360	costRatio = r;
1361	axis = i;
1362	position = p;
1363	}
1364	}
1365
1366	if (costRatio >= mMaxCostRatio)
1367	return false;
1368
1369	Vector3 norm(0,0,0); norm[axis] = 1.0f;
1370	plane = Plane3(norm, position);
1371
1372	return true;
1373	}
1374
1375
1376	Plane3 BspTree::SelectPlane(BspLeaf *leaf, BspTraversalData &data)
1377	{
1378	if ((!mMaxPolyCandidates \|\| data.mPolygons->empty()) &&
1379	(!mMaxRayCandidates \|\| data.mRays->empty()))
1380	{
1381	Debug << "Warning: No autopartition polygon candidate available\n";
1382
1383	// return axis aligned split
1384	AxisAlignedBox3 box;
1385	box.Initialize();
1386
1387	// create bounding box of region
1388	box.Include(*data.mPolygons);
1389
1390	const int axis = box.Size().DrivingAxis();
1391	const Vector3 position = (box.Min()[axis] + box.Max()[axis]) * 0.5f;
1392
1393	Vector3 norm(0,0,0); norm[axis] = 1.0f;
1394	return Plane3(norm, position);
1395	}
1396
1397	if ((mSplitPlaneStrategy & AXIS_ALIGNED) &&
1398	((int)data.mPolygons->size() > mTermMinPolysForAxisAligned) &&
1399	((int)data.mRays->size() > mTermMinRaysForAxisAligned) &&
1400	((mTermMinObjectsForAxisAligned < 0) \|\|
1401	(Polygon3::ParentObjectsSize(*data.mPolygons) > mTermMinObjectsForAxisAligned)))
1402	{
1403	Plane3 plane;
1404	if (SelectAxisAlignedPlane(plane, *data.mPolygons))
1405	return plane;
1406	}
1407
1408	// simplest strategy: just take next polygon
1409	if (mSplitPlaneStrategy & RANDOM_POLYGON)
1410	{
1411	if (!data.mPolygons->empty())
1412	{
1413	Polygon3 *nextPoly =
1414	(*data.mPolygons)[(int)RandomValue(0, (Real)((int)data.mPolygons->size() - 1))];
1415	return nextPoly->GetSupportingPlane();
1416	}
1417	else
1418	{
1419	const int candidateIdx = (int)RandomValue(0, (Real)((int)data.mRays->size() - 1));
1420	BoundedRay bRay = (data.mRays)[candidateIdx];
1421
1422	Ray *ray = bRay->mRay;
1423
1424	const Vector3 minPt = ray->Extrap(bRay->mMinT);
1425	const Vector3 maxPt = ray->Extrap(bRay->mMaxT);
1426
1427	const Vector3 pt = (maxPt + minPt) * 0.5;
1428
1429	const Vector3 normal = ray->GetDir();
1430
1431	return Plane3(normal, pt);
1432	}
1433
1434	return Plane3();
1435	}
1436
1437	// use heuristics to find appropriate plane
1438	return SelectPlaneHeuristics(leaf, data);
1439	}
1440
1441
1442	Plane3 BspTree::ChooseCandidatePlane(const BoundedRayContainer &rays) const
1443	{
1444	const int candidateIdx = (int)RandomValue(0, (Real)((int)rays.size() - 1));
1445	BoundedRay *bRay = rays[candidateIdx];
1446	Ray *ray = bRay->mRay;
1447
1448	const Vector3 minPt = ray->Extrap(bRay->mMinT);
1449	const Vector3 maxPt = ray->Extrap(bRay->mMaxT);
1450
1451	const Vector3 pt = (maxPt + minPt) * 0.5;
1452
1453	const Vector3 normal = ray->GetDir();
1454
1455	return Plane3(normal, pt);
1456	}
1457
1458	Plane3 BspTree::ChooseCandidatePlane2(const BoundedRayContainer &rays) const
1459	{
1460	Vector3 pt[3];
1461	int idx[3];
1462	int cmaxT = 0;
1463	int cminT = 0;
1464	bool chooseMin = false;
1465
1466	for (int j = 0; j < 3; j ++)
1467	{
1468	idx[j] = (int)RandomValue(0, Real((int)rays.size() * 2 - 1));
1469
1470	if (idx[j] >= (int)rays.size())
1471	{
1472	idx[j] -= (int)rays.size();
1473	chooseMin = (cminT < 2);
1474	}
1475	else
1476	chooseMin = (cmaxT < 2);
1477
1478	BoundedRay *bRay = rays[idx[j]];
1479	pt[j] = chooseMin ? bRay->mRay->Extrap(bRay->mMinT) :
1480	bRay->mRay->Extrap(bRay->mMaxT);
1481	}
1482
1483	return Plane3(pt[0], pt[1], pt[2]);
1484	}
1485
1486	Plane3 BspTree::ChooseCandidatePlane3(const BoundedRayContainer &rays) const
1487	{
1488	Vector3 pt[3];
1489
1490	int idx1 = (int)RandomValue(0, (Real)((int)rays.size() - 1));
1491	int idx2 = (int)RandomValue(0, (Real)((int)rays.size() - 1));
1492
1493	// check if rays different
1494	if (idx1 == idx2)
1495	idx2 = (idx2 + 1) % (int)rays.size();
1496
1497	const BoundedRay *ray1 = rays[idx1];
1498	const BoundedRay *ray2 = rays[idx2];
1499
1500	// normal vector of the plane parallel to both lines
1501	const Vector3 norm =
1502	Normalize(CrossProd(ray1->mRay->GetDir(), ray2->mRay->GetDir()));
1503
1504	const Vector3 orig1 = ray1->mRay->Extrap(ray1->mMinT);
1505	const Vector3 orig2 = ray2->mRay->Extrap(ray2->mMinT);
1506
1507	// vector from line 1 to line 2
1508	const Vector3 vd = orig1 - orig2;
1509
1510	// project vector on normal to get distance
1511	const float dist = DotProd(vd, norm);
1512
1513	// point on plane lies halfway between the two planes
1514	const Vector3 planePt = orig1 + norm * dist * 0.5;
1515
1516	return Plane3(norm, planePt);
1517	}
1518
1519
1520	Plane3 BspTree::SelectPlaneHeuristics(BspLeaf *leaf, BspTraversalData &data)
1521	{
1522	float lowestCost = MAX_FLOAT;
1523	Plane3 bestPlane;
1524	// intermediate plane
1525	Plane3 plane;
1526
1527	const int limit = Min((int)data.mPolygons->size(), mMaxPolyCandidates);
1528	int maxIdx = (int)data.mPolygons->size();
1529
1530	for (int i = 0; i < limit; ++ i)
1531	{
1532	// assure that no index is taken twice
1533	const int candidateIdx = (int)RandomValue(0, (Real)(-- maxIdx));
1534
1535	Polygon3 poly = (data.mPolygons)[candidateIdx];
1536
1537	// swap candidate to the end to avoid testing same plane
1538	std::swap((data.mPolygons)[maxIdx], (data.mPolygons)[candidateIdx]);
1539	//Polygon3 poly = (data.mPolygons)[(int)RandomValue(0, (int)polys.size() - 1)];
1540
1541	// evaluate current candidate
1542	const float candidateCost =
1543	SplitPlaneCost(poly->GetSupportingPlane(), data);
1544
1545	if (candidateCost < lowestCost)
1546	{
1547	bestPlane = poly->GetSupportingPlane();
1548	lowestCost = candidateCost;
1549	}
1550	}
1551
1552	//-- choose candidate planes extracted from rays
1553	for (int i = 0; i < mMaxRayCandidates; ++ i)
1554	{
1555	plane = ChooseCandidatePlane3(*data.mRays);
1556	const float candidateCost = SplitPlaneCost(plane, data);
1557
1558	if (candidateCost < lowestCost)
1559	{
1560	bestPlane = plane;
1561	lowestCost = candidateCost;
1562	}
1563	}
1564
1565	#ifdef _DEBUG
1566	Debug << "plane lowest cost: " << lowestCost << endl;
1567	#endif
1568
1569	return bestPlane;
1570	}
1571
1572
1573	float BspTree::SplitPlaneCost(const Plane3 &candidatePlane,
1574	const PolygonContainer &polys) const
1575	{
1576	float val = 0;
1577
1578	float sumBalancedPolys = 0;
1579	float sumSplits = 0;
1580	float sumPolyArea = 0;
1581	float sumBalancedViewCells = 0;
1582	float sumBlockedRays = 0;
1583	float totalBlockedRays = 0;
1584	//float totalArea = 0;
1585	int totalViewCells = 0;
1586
1587	// need three unique ids for each type of view cell
1588	// for balanced view cells criterium
1589	ViewCell::NewMail();
1590	const int backId = ViewCell::sMailId;
1591	ViewCell::NewMail();
1592	const int frontId = ViewCell::sMailId;
1593	ViewCell::NewMail();
1594	const int frontAndBackId = ViewCell::sMailId;
1595
1596	bool useRand;
1597	int limit;
1598
1599	// choose test polyongs randomly if over threshold
1600	if ((int)polys.size() > mMaxTests)
1601	{
1602	useRand = true;
1603	limit = mMaxTests;
1604	}
1605	else
1606	{
1607	useRand = false;
1608	limit = (int)polys.size();
1609	}
1610
1611	for (int i = 0; i < limit; ++ i)
1612	{
1613	const int testIdx = useRand ? (int)RandomValue(0, (Real)(limit - 1)) : i;
1614
1615	Polygon3 *poly = polys[testIdx];
1616
1617	const int classification =
1618	poly->ClassifyPlane(candidatePlane, mEpsilon);
1619
1620	if (mSplitPlaneStrategy & BALANCED_POLYS)
1621	sumBalancedPolys += sBalancedPolysTable[classification];
1622
1623	if (mSplitPlaneStrategy & LEAST_SPLITS)
1624	sumSplits += sLeastPolySplitsTable[classification];
1625
1626	if (mSplitPlaneStrategy & LARGEST_POLY_AREA)
1627	{
1628	if (classification == Polygon3::COINCIDENT)
1629	sumPolyArea += poly->GetArea();
1630	//totalArea += area;
1631	}
1632
1633	if (mSplitPlaneStrategy & BLOCKED_RAYS)
1634	{
1635	const float blockedRays = (float)poly->mPiercingRays.size();
1636
1637	if (classification == Polygon3::COINCIDENT)
1638	sumBlockedRays += blockedRays;
1639
1640	totalBlockedRays += blockedRays;
1641	}
1642
1643	// assign view cells to back or front according to classificaion
1644	if (mSplitPlaneStrategy & BALANCED_VIEW_CELLS)
1645	{
1646	MeshInstance *viewCell = poly->mParent;
1647
1648	// assure that we only count a view cell
1649	// once for the front and once for the back side of the plane
1650	if (classification == Polygon3::FRONT_SIDE)
1651	{
1652	if ((viewCell->mMailbox != frontId) &&
1653	(viewCell->mMailbox != frontAndBackId))
1654	{
1655	sumBalancedViewCells += 1.0;
1656
1657	if (viewCell->mMailbox != backId)
1658	viewCell->mMailbox = frontId;
1659	else
1660	viewCell->mMailbox = frontAndBackId;
1661
1662	++ totalViewCells;
1663	}
1664	}
1665	else if (classification == Polygon3::BACK_SIDE)
1666	{
1667	if ((viewCell->mMailbox != backId) &&
1668	(viewCell->mMailbox != frontAndBackId))
1669	{
1670	sumBalancedViewCells -= 1.0;
1671
1672	if (viewCell->mMailbox != frontId)
1673	viewCell->mMailbox = backId;
1674	else
1675	viewCell->mMailbox = frontAndBackId;
1676
1677	++ totalViewCells;
1678	}
1679	}
1680	}
1681	}
1682
1683	const float polysSize = (float)polys.size() + Limits::Small;
1684
1685	// all values should be approx. between 0 and 1 so they can be combined
1686	// and scaled with the factors according to their importance
1687	if (mSplitPlaneStrategy & BALANCED_POLYS)
1688	val += mBalancedPolysFactor * fabs(sumBalancedPolys) / polysSize;
1689
1690	if (mSplitPlaneStrategy & LEAST_SPLITS)
1691	val += mLeastSplitsFactor * sumSplits / polysSize;
1692
1693	if (mSplitPlaneStrategy & LARGEST_POLY_AREA)
1694	// HACK: polys.size should be total area so scaling is between 0 and 1
1695	val += mLargestPolyAreaFactor * (float)polys.size() / sumPolyArea;
1696
1697	if (mSplitPlaneStrategy & BLOCKED_RAYS)
1698	if (totalBlockedRays != 0)
1699	val += mBlockedRaysFactor * (totalBlockedRays - sumBlockedRays) / totalBlockedRays;
1700
1701	if (mSplitPlaneStrategy & BALANCED_VIEW_CELLS)
1702	val += mBalancedViewCellsFactor * fabs(sumBalancedViewCells) /
1703	((float)totalViewCells + Limits::Small);
1704
1705	return val;
1706	}
1707
1708
1709	inline void BspTree::GenerateUniqueIdsForPvs()
1710	{
1711	ViewCell::NewMail(); sBackId = ViewCell::sMailId;
1712	ViewCell::NewMail(); sFrontId = ViewCell::sMailId;
1713	ViewCell::NewMail(); sFrontAndBackId = ViewCell::sMailId;
1714	}
1715
1716
1717	float BspTree::SplitPlaneCost(const Plane3 &candidatePlane,
1718	const BoundedRayContainer &rays,
1719	const int pvs,
1720	const float probability,
1721	const BspNodeGeometry &cell) const
1722	{
1723	float val = 0;
1724
1725	float sumBalancedRays = 0;
1726	float sumRaySplits = 0;
1727
1728	int frontPvs = 0;
1729	int backPvs = 0;
1730
1731	// probability that view point lies in child
1732	float pOverall = 0;
1733	float pFront = 0;
1734	float pBack = 0;
1735
1736	const bool pvsUseLen = false;
1737
1738	if (mSplitPlaneStrategy & PVS)
1739	{
1740	// create unique ids for pvs heuristics
1741	GenerateUniqueIdsForPvs();
1742
1743	// construct child geometry with regard to the candidate split plane
1744	BspNodeGeometry geomFront;
1745	BspNodeGeometry geomBack;
1746
1747	const bool splitSuccessFull =
1748	cell.SplitGeometry(geomFront,
1749	geomBack,
1750	candidatePlane,
1751	mBox,
1752	mEpsilon);
1753
1754	if (mUseAreaForPvs)
1755	{
1756	pFront = geomFront.GetArea();
1757	pBack = geomBack.GetArea();
1758	}
1759	else
1760	{
1761	pFront = geomFront.GetVolume();
1762	pBack = pOverall - pFront;
1763	}
1764
1765
1766	// give penalty to unbalanced split
1767	if (1 &&
1768	(!splitSuccessFull \|\| (pFront <= 0) \|\| (pBack <= 0) \|\|
1769	!geomFront.Valid() \|\| !geomBack.Valid()))
1770	{
1771	//Debug << "error f: " << pFront << " b: " << pBack << endl;
1772	return 99999.9f;
1773	}
1774
1775	pOverall = probability;
1776	}
1777
1778	bool useRand;
1779	int limit;
1780
1781	// choose test polyongs randomly if over threshold
1782	if ((int)rays.size() > mMaxTests)
1783	{
1784	useRand = true;
1785	limit = mMaxTests;
1786	}
1787	else
1788	{
1789	useRand = false;
1790	limit = (int)rays.size();
1791	}
1792
1793	for (int i = 0; i < limit; ++ i)
1794	{
1795	const int testIdx = useRand ? (int)RandomValue(0, (Real)(limit - 1)) : i;
1796
1797	BoundedRay *bRay = rays[testIdx];
1798
1799	Ray *ray = bRay->mRay;
1800	const float minT = bRay->mMinT;
1801	const float maxT = bRay->mMaxT;
1802
1803	Vector3 entP, extP;
1804
1805	const int cf =
1806	ray->ClassifyPlane(candidatePlane, minT, maxT, entP, extP);
1807
1808	if (mSplitPlaneStrategy & LEAST_RAY_SPLITS)
1809	{
1810	sumBalancedRays += sBalancedRaysTable[cf];
1811	}
1812
1813	if (mSplitPlaneStrategy & BALANCED_RAYS)
1814	{
1815	sumRaySplits += sLeastRaySplitsTable[cf];
1816	}
1817
1818	if (mSplitPlaneStrategy & PVS)
1819	{
1820	// in case the ray intersects an object
1821	// assure that we only count the object
1822	// once for the front and once for the back side of the plane
1823
1824	// add the termination object
1825	if (!ray->intersections.empty())
1826	AddObjToPvs(ray->intersections[0].mObject, cf, frontPvs, backPvs);
1827
1828	// add the source object
1829	AddObjToPvs(ray->sourceObject.mObject, cf, frontPvs, backPvs);
1830	}
1831	}
1832
1833	const float raysSize = (float)rays.size() + Limits::Small;
1834
1835	if (mSplitPlaneStrategy & LEAST_RAY_SPLITS)
1836	val += mLeastRaySplitsFactor * sumRaySplits / raysSize;
1837
1838	if (mSplitPlaneStrategy & BALANCED_RAYS)
1839	val += mBalancedRaysFactor * fabs(sumBalancedRays) / raysSize;
1840
1841	const float denom = pOverall * (float)pvs + Limits::Small;
1842
1843	if (mSplitPlaneStrategy & PVS)
1844	{
1845	val += mPvsFactor * (frontPvs * pFront + (backPvs * pBack)) / denom;
1846	}
1847
1848
1849	#ifdef _DEBUG
1850	Debug << "totalpvs: " << pvs << " ptotal: " << pOverall
1851	<< " frontpvs: " << frontPvs << " pFront: " << pFront
1852	<< " backpvs: " << backPvs << " pBack: " << pBack << endl << endl;
1853	#endif
1854
1855	return val;
1856	}
1857
1858	void BspTree::AddObjToPvs(Intersectable *obj,
1859	const int cf,
1860	int &frontPvs,
1861	int &backPvs) const
1862	{
1863	if (!obj)
1864	return;
1865	// TODO: does this really belong to no pvs?
1866	//if (cf == Ray::COINCIDENT) return;
1867
1868	// object belongs to both PVS
1869	const bool bothSides = (cf == Ray::FRONT_BACK) \|\|
1870	(cf == Ray::BACK_FRONT) \|\|
1871	(cf == Ray::COINCIDENT);
1872
1873	if ((cf == Ray::FRONT) \|\| bothSides)
1874	{
1875	if ((obj->mMailbox != sFrontId) &&
1876	(obj->mMailbox != sFrontAndBackId))
1877	{
1878	++ frontPvs;
1879
1880	if (obj->mMailbox == sBackId)
1881	obj->mMailbox = sFrontAndBackId;
1882	else
1883	obj->mMailbox = sFrontId;
1884	}
1885	}
1886
1887	if ((cf == Ray::BACK) \|\| bothSides)
1888	{
1889	if ((obj->mMailbox != sBackId) &&
1890	(obj->mMailbox != sFrontAndBackId))
1891	{
1892	++ backPvs;
1893
1894	if (obj->mMailbox == sFrontId)
1895	obj->mMailbox = sFrontAndBackId;
1896	else
1897	obj->mMailbox = sBackId;
1898	}
1899	}
1900	}
1901
1902
1903	float BspTree::SplitPlaneCost(const Plane3 &candidatePlane,
1904	BspTraversalData &data) const
1905	{
1906	float val = 0;
1907
1908	if (mSplitPlaneStrategy & VERTICAL_AXIS)
1909	{
1910	Vector3 tinyAxis(0,0,0); tinyAxis[mBox.Size().TinyAxis()] = 1.0f;
1911	// we put a penalty on the dot product between the "tiny" vertical axis
1912	// and the split plane axis
1913	val += mVerticalSplitsFactor *
1914	fabs(DotProd(candidatePlane.mNormal, tinyAxis));
1915	}
1916
1917	// the following criteria loop over all polygons to find the cost value
1918	if ((mSplitPlaneStrategy & BALANCED_POLYS) \|\|
1919	(mSplitPlaneStrategy & LEAST_SPLITS) \|\|
1920	(mSplitPlaneStrategy & LARGEST_POLY_AREA) \|\|
1921	(mSplitPlaneStrategy & BALANCED_VIEW_CELLS) \|\|
1922	(mSplitPlaneStrategy & BLOCKED_RAYS))
1923	{
1924	val += SplitPlaneCost(candidatePlane, *data.mPolygons);
1925	}
1926
1927	// the following criteria loop over all rays to find the cost value
1928	if ((mSplitPlaneStrategy & BALANCED_RAYS) \|\|
1929	(mSplitPlaneStrategy & LEAST_RAY_SPLITS) \|\|
1930	(mSplitPlaneStrategy & PVS))
1931	{
1932	val += SplitPlaneCost(candidatePlane, *data.mRays, data.mPvs,
1933	data.mProbability, *data.mGeometry);
1934	}
1935
1936	// return linear combination of the sums
1937	return val;
1938	}
1939
1940	void BspTree::CollectLeaves(vector<BspLeaf *> &leaves) const
1941	{
1942	stack<BspNode *> nodeStack;
1943	nodeStack.push(mRoot);
1944
1945	while (!nodeStack.empty())
1946	{
1947	BspNode *node = nodeStack.top();
1948
1949	nodeStack.pop();
1950
1951	if (node->IsLeaf())
1952	{
1953	BspLeaf leaf = (BspLeaf )node;
1954	leaves.push_back(leaf);
1955	}
1956	else
1957	{
1958	BspInterior interior = dynamic_cast<BspInterior >(node);
1959
1960	nodeStack.push(interior->GetBack());
1961	nodeStack.push(interior->GetFront());
1962	}
1963	}
1964	}
1965
1966
1967	AxisAlignedBox3 BspTree::GetBoundingBox() const
1968	{
1969	return mBox;
1970	}
1971
1972
1973	void BspTree::EvaluateLeafStats(const BspTraversalData &data)
1974	{
1975	// the node became a leaf -> evaluate stats for leafs
1976	BspLeaf leaf = dynamic_cast<BspLeaf >(data.mNode);
1977
1978	// store maximal and minimal depth
1979	if (data.mDepth > mStat.maxDepth)
1980	mStat.maxDepth = data.mDepth;
1981
1982	if (data.mDepth < mStat.minDepth)
1983	mStat.minDepth = data.mDepth;
1984
1985	// accumulate depth to compute average depth
1986	mStat.accumDepth += data.mDepth;
1987	// accumulate rays to compute rays / leaf
1988	mStat.accumRays += (int)data.mRays->size();
1989
1990	if (data.mDepth >= mTermMaxDepth)
1991	++ mStat.maxDepthNodes;
1992
1993	if (data.mPvs < mTermMinPvs)
1994	++ mStat.minPvsNodes;
1995
1996	if ((int)data.mRays->size() < mTermMinRays)
1997	++ mStat.minRaysNodes;
1998
1999	if (data.GetAvgRayContribution() > mTermMaxRayContribution)
2000	++ mStat.maxRayContribNodes;
2001
2002	if (data.mProbability <= mTermMinProbability)
2003	++ mStat.minProbabilityNodes;
2004
2005	#ifdef _DEBUG
2006	Debug << "BSP stats: "
2007	<< "Depth: " << data.mDepth << " (max: " << mTermMaxDepth << "), "
2008	<< "PVS: " << data.mPvs << " (min: " << mTermMinPvs << "), "
2009	<< "Probability: " << data.mProbability << " (min: " << mTermMinProbability << "), "
2010	<< "#polygons: " << (int)data.mPolygons->size() << " (max: " << mTermMinPolys << "), "
2011	<< "#rays: " << (int)data.mRays->size() << " (max: " << mTermMinRays << "), "
2012	<< "#pvs: " << leaf->GetViewCell()->GetPvs().GetSize() << "=, "
2013	<< "#avg ray contrib (pvs): " << (float)data.mPvs / (float)data.mRays->size() << endl;
2014	#endif
2015	}
2016
2017
2018	int BspTree::_CastRay(Ray &ray)
2019	{
2020	int hits = 0;
2021
2022	stack<BspRayTraversalData> tStack;
2023
2024	float maxt, mint;
2025
2026	if (!mBox.GetRaySegment(ray, mint, maxt))
2027	return 0;
2028
2029	ViewCell::NewMail();
2030
2031	Vector3 entp = ray.Extrap(mint);
2032	Vector3 extp = ray.Extrap(maxt);
2033
2034	BspNode *node = mRoot;
2035	BspNode *farChild = NULL;
2036
2037	while (1)
2038	{
2039	if (!node->IsLeaf())
2040	{
2041	BspInterior in = dynamic_cast<BspInterior >(node);
2042
2043	Plane3 splitPlane = in->GetPlane();
2044	const int entSide = splitPlane.Side(entp);
2045	const int extSide = splitPlane.Side(extp);
2046
2047	if (entSide < 0)
2048	{
2049	node = in->GetBack();
2050
2051	if(extSide <= 0) // plane does not split ray => no far child
2052	continue;
2053
2054	farChild = in->GetFront(); // plane splits ray
2055
2056	} else if (entSide > 0)
2057	{
2058	node = in->GetFront();
2059
2060	if (extSide >= 0) // plane does not split ray => no far child
2061	continue;
2062
2063	farChild = in->GetBack(); // plane splits ray
2064	}
2065	else // ray and plane are coincident
2066	{
2067	// WHAT TO DO IN THIS CASE ?
2068	//break;
2069	node = in->GetFront();
2070	continue;
2071	}
2072
2073	// push data for far child
2074	tStack.push(BspRayTraversalData(farChild, extp, maxt));
2075
2076	// find intersection of ray segment with plane
2077	float t;
2078	extp = splitPlane.FindIntersection(ray.GetLoc(), extp, &t);
2079	maxt *= t;
2080
2081	} else // reached leaf => intersection with view cell
2082	{
2083	BspLeaf leaf = dynamic_cast<BspLeaf >(node);
2084
2085	if (!leaf->mViewCell->Mailed())
2086	{
2087	//ray.bspIntersections.push_back(Ray::BspIntersection(maxt, leaf));
2088	leaf->mViewCell->Mail();
2089	++ hits;
2090	}
2091
2092	//-- fetch the next far child from the stack
2093	if (tStack.empty())
2094	break;
2095
2096	entp = extp;
2097	mint = maxt; // NOTE: need this?
2098
2099	if (ray.GetType() == Ray::LINE_SEGMENT && mint > 1.0f)
2100	break;
2101
2102	BspRayTraversalData &s = tStack.top();
2103
2104	node = s.mNode;
2105	extp = s.mExitPoint;
2106	maxt = s.mMaxT;
2107
2108	tStack.pop();
2109	}
2110	}
2111
2112	return hits;
2113	}
2114
2115
2116	int BspTree::CastLineSegment(const Vector3 &origin,
2117	const Vector3 &termination,
2118	ViewCellContainer &viewcells)
2119	{
2120	int hits = 0;
2121	stack<BspRayTraversalData> tStack;
2122
2123	float mint = 0.0f, maxt = 1.0f;
2124
2125	Intersectable::NewMail();
2126	ViewCell::NewMail();
2127
2128	Vector3 entp = origin;
2129	Vector3 extp = termination;
2130
2131	BspNode *node = mRoot;
2132	BspNode *farChild = NULL;
2133
2134
2135	const float thresh = 1 ? 1e-6f : 0.0f;
2136
2137	while (1)
2138	{
2139	if (!node->IsLeaf())
2140	{
2141	BspInterior in = dynamic_cast<BspInterior >(node);
2142
2143	Plane3 splitPlane = in->GetPlane();
2144
2145	const int entSide = splitPlane.Side(entp, thresh);
2146	const int extSide = splitPlane.Side(extp, thresh);
2147
2148	if (entSide < 0)
2149	{
2150	node = in->GetBack();
2151
2152	// plane does not split ray => no far child
2153	if (extSide <= 0)
2154	continue;
2155
2156	farChild = in->GetFront(); // plane splits ray
2157	}
2158	else if (entSide > 0)
2159	{
2160	node = in->GetFront();
2161
2162	if (extSide >= 0) // plane does not split ray => no far child
2163	continue;
2164
2165	farChild = in->GetBack(); // plane splits ray
2166	}
2167	else // one of the ray end points is on the plane
2168	{ // NOTE: what to do if ray is coincident with plane?
2169	if (extSide < 0)
2170	node = in->GetBack();
2171	else //if (extSide > 0)
2172	node = in->GetFront();
2173	//else break; // coincident => count no intersections
2174
2175	continue; // no far child
2176	}
2177
2178	// push data for far child
2179	tStack.push(BspRayTraversalData(farChild, extp, maxt));
2180
2181	// find intersection of ray segment with plane
2182	float t;
2183	extp = splitPlane.FindIntersection(origin, extp, &t);
2184	maxt *= t;
2185	}
2186	else
2187	{
2188	// reached leaf => intersection with view cell
2189	BspLeaf leaf = dynamic_cast<BspLeaf >(node);
2190
2191	if (!leaf->mViewCell->Mailed())
2192	{
2193	viewcells.push_back(leaf->mViewCell);
2194	leaf->mViewCell->Mail();
2195	hits++;
2196	}
2197
2198	//-- fetch the next far child from the stack
2199	if (tStack.empty())
2200	break;
2201
2202	entp = extp;
2203	mint = maxt; // NOTE: need this?
2204
2205	BspRayTraversalData &s = tStack.top();
2206
2207	node = s.mNode;
2208	extp = s.mExitPoint;
2209	maxt = s.mMaxT;
2210
2211	tStack.pop();
2212	}
2213	}
2214
2215	return hits;
2216	}
2217
2218
2219	void BspTree::CollectViewCells(ViewCellContainer &viewCells) const
2220	{
2221	stack<BspNode *> nodeStack;
2222	nodeStack.push(mRoot);
2223
2224	ViewCell::NewMail();
2225
2226	while (!nodeStack.empty())
2227	{
2228	BspNode *node = nodeStack.top();
2229	nodeStack.pop();
2230
2231	if (node->IsLeaf())
2232	{
2233	ViewCellLeaf viewCell = dynamic_cast<BspLeaf >(node)->mViewCell;
2234
2235	if (!viewCell->Mailed())
2236	{
2237	viewCell->Mail();
2238	viewCells.push_back(viewCell);
2239	}
2240	}
2241	else
2242	{
2243	BspInterior interior = dynamic_cast<BspInterior >(node);
2244
2245	nodeStack.push(interior->GetFront());
2246	nodeStack.push(interior->GetBack());
2247	}
2248	}
2249	}
2250
2251
2252	BspTreeStatistics &BspTree::GetStat()
2253	{
2254	return mStat;
2255	}
2256
2257
2258	float BspTree::AccumulatedRayLength(BoundedRayContainer &rays) const
2259	{
2260	float len = 0;
2261
2262	BoundedRayContainer::const_iterator it, it_end = rays.end();
2263
2264	for (it = rays.begin(); it != it_end; ++ it)
2265	{
2266	len += SqrDistance((it)->mRay->Extrap((it)->mMinT),
2267	(it)->mRay->Extrap((it)->mMaxT));
2268	}
2269
2270	return len;
2271	}
2272
2273
2274	int BspTree::SplitRays(const Plane3 &plane,
2275	BoundedRayContainer &rays,
2276	BoundedRayContainer &frontRays,
2277	BoundedRayContainer &backRays)
2278	{
2279	int splits = 0;
2280
2281	while (!rays.empty())
2282	{
2283	BoundedRay *bRay = rays.back();
2284	Ray *ray = bRay->mRay;
2285	float minT = bRay->mMinT;
2286	float maxT = bRay->mMaxT;
2287
2288	rays.pop_back();
2289
2290	Vector3 entP, extP;
2291
2292	const int cf =
2293	ray->ClassifyPlane(plane, minT, maxT, entP, extP);
2294
2295	// set id to ray classification
2296	ray->SetId(cf);
2297
2298	switch (cf)
2299	{
2300	case Ray::COINCIDENT: // TODO: should really discard ray?
2301	frontRays.push_back(bRay);
2302	//DEL_PTR(bRay);
2303	break;
2304	case Ray::BACK:
2305	backRays.push_back(bRay);
2306	break;
2307	case Ray::FRONT:
2308	frontRays.push_back(bRay);
2309	break;
2310	case Ray::FRONT_BACK:
2311	{
2312	// find intersection of ray segment with plane
2313	const float t = plane.FindT(ray->GetLoc(), extP);
2314
2315	const float newT = t * maxT;
2316
2317	frontRays.push_back(new BoundedRay(ray, minT, newT));
2318	backRays.push_back(new BoundedRay(ray, newT, maxT));
2319
2320	DEL_PTR(bRay);
2321	}
2322	break;
2323	case Ray::BACK_FRONT:
2324	{
2325	// find intersection of ray segment with plane
2326	const float t = plane.FindT(ray->GetLoc(), extP);
2327	const float newT = t * bRay->mMaxT;
2328
2329	backRays.push_back(new BoundedRay(ray, minT, newT));
2330	frontRays.push_back(new BoundedRay(ray, newT, maxT));
2331
2332	DEL_PTR(bRay);
2333
2334	++ splits;
2335	}
2336	break;
2337	default:
2338	Debug << "Should not come here 4" << endl;
2339	break;
2340	}
2341	}
2342
2343	return splits;
2344	}
2345
2346	void BspTree::ExtractHalfSpaces(BspNode *n, vector<Plane3> &halfSpaces) const
2347	{
2348	BspNode *lastNode;
2349
2350	do
2351	{
2352	lastNode = n;
2353
2354	// want to get planes defining geometry of this node => don't take
2355	// split plane of node itself
2356	n = n->GetParent();
2357
2358	if (n)
2359	{
2360	BspInterior interior = dynamic_cast<BspInterior >(n);
2361	Plane3 halfSpace = dynamic_cast<BspInterior *>(interior)->GetPlane();
2362
2363	if (interior->GetBack() != lastNode)
2364	halfSpace.ReverseOrientation();
2365
2366	halfSpaces.push_back(halfSpace);
2367	}
2368	}
2369	while (n);
2370	}
2371
2372
2373
2374	void BspTree::ConstructGeometry(ViewCell *vc,
2375	BspNodeGeometry &vcGeom) const
2376	{
2377	ViewCellContainer leaves;
2378	mViewCellsTree->CollectLeaves(vc, leaves);
2379
2380	ViewCellContainer::const_iterator it, it_end = leaves.end();
2381
2382	for (it = leaves.begin(); it != it_end; ++ it)
2383	{
2384	BspLeaf l = dynamic_cast<BspViewCell >(*it)->mLeaf;
2385	ConstructGeometry(l, vcGeom);
2386	}
2387	}
2388
2389
2390	void BspTree::ConstructGeometry(BspNode *n,
2391	BspNodeGeometry &geom) const
2392	{
2393	vector<Plane3> halfSpaces;
2394	ExtractHalfSpaces(n, halfSpaces);
2395
2396	PolygonContainer candidatePolys;
2397	vector<Plane3> candidatePlanes;
2398
2399	vector<Plane3>::const_iterator pit, pit_end = halfSpaces.end();
2400
2401	// bounded planes are added to the polygons
2402	for (pit = halfSpaces.begin(); pit != pit_end; ++ pit)
2403	{
2404	Polygon3 p = GetBoundingBox().CrossSection(pit);
2405
2406	if (p->Valid(mEpsilon))
2407	{
2408	candidatePolys.push_back(p);
2409	candidatePlanes.push_back(*pit);
2410	}
2411	}
2412
2413	// add faces of bounding box (also could be faces of the cell)
2414	for (int i = 0; i < 6; ++ i)
2415	{
2416	VertexContainer vertices;
2417
2418	for (int j = 0; j < 4; ++ j)
2419	vertices.push_back(mBox.GetFace(i).mVertices[j]);
2420
2421	Polygon3 *poly = new Polygon3(vertices);
2422
2423	candidatePolys.push_back(poly);
2424	candidatePlanes.push_back(poly->GetSupportingPlane());
2425	}
2426
2427	for (int i = 0; i < (int)candidatePolys.size(); ++ i)
2428	{
2429	// polygon is split by all other planes
2430	for (int j = 0; (j < (int)halfSpaces.size()) && candidatePolys[i]; ++ j)
2431	{
2432	if (i == j) // polygon and plane are coincident
2433	continue;
2434
2435	VertexContainer splitPts;
2436	Polygon3 frontPoly, backPoly;
2437
2438	const int cf =
2439	candidatePolys[i]->ClassifyPlane(halfSpaces[j],
2440	mEpsilon);
2441
2442	switch (cf)
2443	{
2444	case Polygon3::SPLIT:
2445	frontPoly = new Polygon3();
2446	backPoly = new Polygon3();
2447
2448	candidatePolys[i]->Split(halfSpaces[j],
2449	*frontPoly,
2450	*backPoly,
2451	mEpsilon);
2452
2453	DEL_PTR(candidatePolys[i]);
2454
2455	if (backPoly->Valid(mEpsilon))
2456	candidatePolys[i] = backPoly;
2457	else
2458	DEL_PTR(backPoly);
2459
2460	// outside, don't need this
2461	DEL_PTR(frontPoly);
2462	break;
2463	// polygon outside of halfspace
2464	case Polygon3::FRONT_SIDE:
2465	DEL_PTR(candidatePolys[i]);
2466	break;
2467	// just take polygon as it is
2468	case Polygon3::BACK_SIDE:
2469	case Polygon3::COINCIDENT:
2470	default:
2471	break;
2472	}
2473	}
2474
2475	if (candidatePolys[i])
2476	{
2477	geom.Add(candidatePolys[i], candidatePlanes[i]);
2478	}
2479	}
2480	}
2481
2482
2483	void BspTree::SetViewCellsManager(ViewCellsManager *vcm)
2484	{
2485	mViewCellsManager = vcm;
2486	}
2487
2488
2489	typedef pair<BspNode , BspNodeGeometry > bspNodePair;
2490
2491
2492	int BspTree::FindNeighbors(BspNode *n,
2493	vector<BspLeaf *> &neighbors,
2494	const bool onlyUnmailed) const
2495	{
2496	stack<bspNodePair> nodeStack;
2497
2498	BspNodeGeometry nodeGeom;
2499	ConstructGeometry(n, nodeGeom);
2500
2501	// split planes from the root to this node
2502	// needed to verify that we found neighbor leaf
2503	// TODO: really needed?
2504	vector<Plane3> halfSpaces;
2505	ExtractHalfSpaces(n, halfSpaces);
2506
2507
2508	BspNodeGeometry *rgeom = new BspNodeGeometry();
2509	ConstructGeometry(mRoot, *rgeom);
2510
2511	nodeStack.push(bspNodePair(mRoot, rgeom));
2512
2513	while (!nodeStack.empty())
2514	{
2515	BspNode *node = nodeStack.top().first;
2516	BspNodeGeometry *geom = nodeStack.top().second;
2517
2518	nodeStack.pop();
2519
2520	if (node->IsLeaf())
2521	{
2522	// test if this leaf is in valid view space
2523	if (node->TreeValid() &&
2524	(node != n) &&
2525	(!onlyUnmailed \|\| !node->Mailed()))
2526	{
2527	bool isAdjacent = true;
2528
2529	if (1)
2530	{
2531	// test all planes of current node if still adjacent
2532	for (int i = 0; (i < halfSpaces.size()) && isAdjacent; ++ i)
2533	{
2534	const int cf =
2535	Polygon3::ClassifyPlane(geom->GetPolys(),
2536	halfSpaces[i],
2537	mEpsilon);
2538
2539	if (cf == Polygon3::FRONT_SIDE)
2540	{
2541	isAdjacent = false;
2542	}
2543	}
2544	}
2545	else
2546	{
2547	// TODO: why is this wrong??
2548	// test all planes of current node if still adjacent
2549	for (int i = 0; (i < nodeGeom.Size()) && isAdjacent; ++ i)
2550	{
2551	Polygon3 *poly = nodeGeom.GetPolys()[i];
2552
2553	const int cf =
2554	Polygon3::ClassifyPlane(geom->GetPolys(),
2555	poly->GetSupportingPlane(),
2556	mEpsilon);
2557
2558	if (cf == Polygon3::FRONT_SIDE)
2559	{
2560	isAdjacent = false;
2561	}
2562	}
2563	}
2564	// neighbor was found
2565	if (isAdjacent)
2566	{
2567	neighbors.push_back(dynamic_cast<BspLeaf *>(node));
2568	}
2569	}
2570	}
2571	else
2572	{
2573	BspInterior interior = dynamic_cast<BspInterior >(node);
2574
2575	const int cf = Polygon3::ClassifyPlane(nodeGeom.GetPolys(),
2576	interior->GetPlane(),
2577	mEpsilon);
2578
2579	BspNode *front = interior->GetFront();
2580	BspNode *back = interior->GetBack();
2581
2582	BspNodeGeometry *fGeom = new BspNodeGeometry();
2583	BspNodeGeometry *bGeom = new BspNodeGeometry();
2584
2585	geom->SplitGeometry(*fGeom,
2586	*bGeom,
2587	interior->GetPlane(),
2588	mBox,
2589	//0.0000001f);
2590	mEpsilon);
2591
2592	if (cf == Polygon3::BACK_SIDE)
2593	{
2594	nodeStack.push(bspNodePair(interior->GetBack(), bGeom));
2595	DEL_PTR(fGeom);
2596	}
2597	else
2598	{
2599	if (cf == Polygon3::FRONT_SIDE)
2600	{
2601	nodeStack.push(bspNodePair(interior->GetFront(), fGeom));
2602	DEL_PTR(bGeom);
2603	}
2604	else
2605	{ // random decision
2606	nodeStack.push(bspNodePair(front, fGeom));
2607	nodeStack.push(bspNodePair(back, bGeom));
2608	}
2609	}
2610	}
2611
2612	DEL_PTR(geom);
2613	}
2614
2615	return (int)neighbors.size();
2616	}
2617
2618
2619	BspLeaf *BspTree::GetRandomLeaf(const bool onlyUnmailed)
2620	{
2621	stack<BspNode *> nodeStack;
2622
2623	nodeStack.push(mRoot);
2624
2625	int mask = rand();
2626
2627	while (!nodeStack.empty())
2628	{
2629	BspNode *node = nodeStack.top();
2630	nodeStack.pop();
2631
2632	if (node->IsLeaf())
2633	{
2634	if ( (!onlyUnmailed \|\| !node->Mailed()) )
2635	return dynamic_cast<BspLeaf *>(node);
2636	}
2637	else
2638	{
2639	BspInterior interior = dynamic_cast<BspInterior >(node);
2640
2641	// random decision
2642	if (mask & 1)
2643	nodeStack.push(interior->GetBack());
2644	else
2645	nodeStack.push(interior->GetFront());
2646
2647	mask = mask >> 1;
2648	}
2649	}
2650
2651	return NULL;
2652	}
2653
2654
2655	void BspTree::AddToPvs(BspLeaf *leaf,
2656	const BoundedRayContainer &rays,
2657	int &sampleContributions,
2658	int &contributingSamples)
2659	{
2660	sampleContributions = 0;
2661	contributingSamples = 0;
2662
2663	BoundedRayContainer::const_iterator it, it_end = rays.end();
2664
2665	ViewCellLeaf *vc = leaf->GetViewCell();
2666
2667	// add contributions from samples to the PVS
2668	for (it = rays.begin(); it != it_end; ++ it)
2669	{
2670	int contribution = 0;
2671	Ray ray = (it)->mRay;
2672	float relContribution;
2673	if (!ray->intersections.empty())
2674	contribution += vc->GetPvs().AddSample(ray->intersections[0].mObject,
2675	1.0f,
2676	relContribution);
2677
2678	if (ray->sourceObject.mObject)
2679	contribution += vc->GetPvs().AddSample(ray->sourceObject.mObject,
2680	1.0f,
2681	relContribution);
2682
2683	if (contribution)
2684	{
2685	sampleContributions += contribution;
2686	++ contributingSamples;
2687	}
2688
2689	//if (ray->mFlags & Ray::STORE_BSP_INTERSECTIONS)
2690	// ray->bspIntersections.push_back(Ray::BspIntersection((*it)->mMinT, this));
2691	}
2692	}
2693
2694
2695	int BspTree::ComputePvsSize(const BoundedRayContainer &rays) const
2696	{
2697	int pvsSize = 0;
2698
2699	BoundedRayContainer::const_iterator rit, rit_end = rays.end();
2700
2701	Intersectable::NewMail();
2702
2703	for (rit = rays.begin(); rit != rays.end(); ++ rit)
2704	{
2705	Ray ray = (rit)->mRay;
2706
2707	if (!ray->intersections.empty())
2708	{
2709	if (!ray->intersections[0].mObject->Mailed())
2710	{
2711	ray->intersections[0].mObject->Mail();
2712	++ pvsSize;
2713	}
2714	}
2715	if (ray->sourceObject.mObject)
2716	{
2717	if (!ray->sourceObject.mObject->Mailed())
2718	{
2719	ray->sourceObject.mObject->Mail();
2720	++ pvsSize;
2721	}
2722	}
2723	}
2724
2725	return pvsSize;
2726	}
2727
2728
2729	float BspTree::GetEpsilon() const
2730	{
2731	return mEpsilon;
2732	}
2733
2734
2735	int BspTree::CollectMergeCandidates(const vector<BspLeaf *> leaves,
2736	vector<MergeCandidate> &candidates)
2737	{
2738	BspLeaf::NewMail();
2739
2740	vector<BspLeaf *>::const_iterator it, it_end = leaves.end();
2741
2742	int numCandidates = 0;
2743
2744	// find merge candidates and push them into queue
2745	for (it = leaves.begin(); it != it_end; ++ it)
2746	{
2747	BspLeaf leaf = it;
2748
2749	// the same leaves must not be part of two merge candidates
2750	leaf->Mail();
2751	vector<BspLeaf *> neighbors;
2752	FindNeighbors(leaf, neighbors, true);
2753
2754	vector<BspLeaf *>::const_iterator nit, nit_end = neighbors.end();
2755
2756	// TODO: test if at least one ray goes from one leaf to the other
2757	for (nit = neighbors.begin(); nit != nit_end; ++ nit)
2758	{
2759	if ((*nit)->GetViewCell() != leaf->GetViewCell())
2760	{
2761	MergeCandidate mc(leaf->GetViewCell(), (*nit)->GetViewCell());
2762	candidates.push_back(mc);
2763
2764	++ numCandidates;
2765	if ((numCandidates % 1000) == 0)
2766	{
2767	cout << "collected " << numCandidates << " merge candidates" << endl;
2768	}
2769	}
2770	}
2771	}
2772
2773	Debug << "merge queue: " << (int)candidates.size() << endl;
2774	Debug << "leaves in queue: " << numCandidates << endl;
2775
2776
2777	return (int)leaves.size();
2778	}
2779
2780
2781	int BspTree::CollectMergeCandidates(const VssRayContainer &rays,
2782	vector<MergeCandidate> &candidates)
2783	{
2784	ViewCell::NewMail();
2785	long startTime = GetTime();
2786
2787	map<BspLeaf , vector<BspLeaf> > neighborMap;
2788	ViewCellContainer::const_iterator iit;
2789
2790	int numLeaves = 0;
2791
2792	BspLeaf::NewMail();
2793
2794	for (int i = 0; i < (int)rays.size(); ++ i)
2795	{
2796	VssRay *ray = rays[i];
2797
2798	// traverse leaves stored in the rays and compare and
2799	// merge consecutive leaves (i.e., the neighbors in the tree)
2800	if (ray->mViewCells.size() < 2)
2801	continue;
2802
2803	iit = ray->mViewCells.begin();
2804	BspViewCell bspVc = dynamic_cast<BspViewCell >(*(iit ++));
2805	BspLeaf *leaf = bspVc->mLeaf;
2806
2807	// traverse intersections
2808	// consecutive leaves are neighbors => add them to queue
2809	for (; iit != ray->mViewCells.end(); ++ iit)
2810	{
2811	// next pair
2812	BspLeaf *prevLeaf = leaf;
2813	bspVc = dynamic_cast<BspViewCell >(iit);
2814	leaf = bspVc->mLeaf;
2815
2816	// view space not valid or same view cell
2817	if (!leaf->TreeValid() \|\| !prevLeaf->TreeValid() \|\|
2818	(leaf->GetViewCell() == prevLeaf->GetViewCell()))
2819	continue;
2820
2821	vector<BspLeaf *> &neighbors = neighborMap[leaf];
2822
2823	bool found = false;
2824
2825	// both leaves inserted in queue already =>
2826	// look if double pair already exists
2827	if (leaf->Mailed() && prevLeaf->Mailed())
2828	{
2829	vector<BspLeaf *>::const_iterator it, it_end = neighbors.end();
2830
2831	for (it = neighbors.begin(); !found && (it != it_end); ++ it)
2832	if (*it == prevLeaf)
2833	found = true; // already in queue
2834	}
2835
2836	if (!found)
2837	{
2838	// this pair is not in map yet
2839	// => insert into the neighbor map and the queue
2840	neighbors.push_back(prevLeaf);
2841	neighborMap[prevLeaf].push_back(leaf);
2842
2843	leaf->Mail();
2844	prevLeaf->Mail();
2845
2846	MergeCandidate mc(leaf->GetViewCell(), prevLeaf->GetViewCell());
2847
2848	candidates.push_back(mc);
2849
2850	if (((int)candidates.size() % 1000) == 0)
2851	{
2852	cout << "collected " << (int)candidates.size() << " merge candidates" << endl;
2853	}
2854	}
2855	}
2856	}
2857
2858	Debug << "neighbormap size: " << (int)neighborMap.size() << endl;
2859	Debug << "merge queue: " << (int)candidates.size() << endl;
2860	Debug << "leaves in queue: " << numLeaves << endl;
2861
2862
2863	//-- collect the leaves which haven't been found by ray casting
2864	#if 0
2865	cout << "finding additional merge candidates using geometry" << endl;
2866	vector<BspLeaf *> leaves;
2867	CollectLeaves(leaves, true);
2868	Debug << "found " << (int)leaves.size() << " new leaves" << endl << endl;
2869	CollectMergeCandidates(leaves, candidates);
2870	#endif
2871
2872	return numLeaves;
2873	}
2874
2875
2876
2877
2878	/***************************************************************/
2879	/* BspNodeGeometry Implementation */
2880	/***************************************************************/
2881
2882
2883	BspNodeGeometry::BspNodeGeometry(const BspNodeGeometry &rhs)
2884	{
2885	mPolys.reserve(rhs.mPolys.size());
2886	mPlanes.reserve(rhs.mPolys.size());
2887
2888	PolygonContainer::const_iterator it, it_end = rhs.mPolys.end();
2889
2890	int i = 0;
2891
2892	for (it = rhs.mPolys.begin(); it != it_end; ++ it, ++i)
2893	{
2894	Polygon3 poly = it;
2895	Add(new Polygon3(*poly), rhs.mPlanes[i]);
2896	}
2897	}
2898
2899
2900	BspNodeGeometry& BspNodeGeometry::operator=(const BspNodeGeometry& g)
2901	{
2902	if (this == &g)
2903	return *this;
2904
2905	CLEAR_CONTAINER(mPolys);
2906
2907	mPolys.reserve(g.mPolys.size());
2908	mPlanes.reserve(g.mPolys.size());
2909
2910	PolygonContainer::const_iterator it, it_end = g.mPolys.end();
2911
2912	int i = 0;
2913
2914	for (it = g.mPolys.begin(); it != it_end; ++ it, ++ i)
2915	{
2916	Polygon3 poly = it;
2917	Add(new Polygon3(*poly), g.mPlanes[i]);
2918	}
2919
2920	return *this;
2921	}
2922
2923
2924	BspNodeGeometry::BspNodeGeometry(const PolygonContainer &polys)
2925	{
2926	mPolys = polys;
2927	mPlanes.reserve(polys.size());
2928
2929	PolygonContainer::const_iterator it, it_end = polys.end();
2930
2931	for (it = polys.begin(); it != it_end; ++ it)
2932	{
2933	Polygon3 poly = it;
2934	mPlanes.push_back(poly->GetSupportingPlane());
2935	}
2936	}
2937
2938
2939	BspNodeGeometry::~BspNodeGeometry()
2940	{
2941	CLEAR_CONTAINER(mPolys);
2942	}
2943
2944
2945	int BspNodeGeometry::Size() const
2946	{
2947	return (int)mPolys.size();
2948	}
2949
2950
2951	const PolygonContainer &BspNodeGeometry::GetPolys()
2952	{
2953	return mPolys;
2954	}
2955
2956
2957	void BspNodeGeometry::Add(Polygon3 *p, const Plane3 &plane)
2958	{
2959	mPolys.push_back(p);
2960	mPlanes.push_back(plane);
2961	}
2962
2963
2964	float BspNodeGeometry::GetArea() const
2965	{
2966	return Polygon3::GetArea(mPolys);
2967	}
2968
2969
2970	float BspNodeGeometry::GetVolume() const
2971	{
2972	//-- compute volume using tetrahedralization of the geometry
2973	// and adding the volume of the single tetrahedrons
2974	float volume = 0;
2975	const float f = 1.0f / 6.0f;
2976
2977	PolygonContainer::const_iterator pit, pit_end = mPolys.end();
2978
2979	// note: can take arbitrary point, e.g., the origin. However,
2980	// we rather take the center of mass to prevents precision errors
2981	const Vector3 center = CenterOfMass();
2982
2983	for (pit = mPolys.begin(); pit != pit_end; ++ pit)
2984	{
2985	Polygon3 poly = pit;
2986	const Vector3 v0 = poly->mVertices[0] - center;
2987
2988	for (int i = 1; i < (int)poly->mVertices.size() - 1; ++ i)
2989	{
2990	const Vector3 v1 = poly->mVertices[i] - center;
2991	const Vector3 v2 = poly->mVertices[i + 1] - center;
2992
2993	// more robust version using abs and the center of mass
2994	volume += fabs (f * (DotProd(v0, CrossProd(v1, v2))));
2995	}
2996	}
2997
2998	return volume;
2999	}
3000
3001
3002	void BspNodeGeometry::GetBoundingBox(AxisAlignedBox3 &box) const
3003	{
3004	box.Initialize();
3005	box.Include(mPolys);
3006	}
3007
3008
3009	int BspNodeGeometry::Side(const Plane3 &plane, const float eps) const
3010	{
3011	PolygonContainer::const_iterator it, it_end = mPolys.end();
3012
3013	bool onFrontSide = false;
3014	bool onBackSide = false;
3015
3016	for (it = mPolys.begin(); it != it_end; ++ it)
3017	{
3018	const int side = (*it)->Side(plane, eps);
3019
3020	if (side == -1)
3021	onBackSide = true;
3022	else if (side == 1)
3023	onFrontSide = true;
3024
3025	if ((side == 0) \|\| (onBackSide && onFrontSide))
3026	return 0;
3027	}
3028
3029	if (onFrontSide)
3030	return 1;
3031
3032	return -1;
3033	}
3034
3035
3036	int BspNodeGeometry::ComputeIntersection(const AxisAlignedBox3 &box) const
3037	{
3038	// 1: box does not intersect geometry
3039	// 0: box intersects geometry
3040	// -1: box contains geometry
3041
3042	AxisAlignedBox3 boundingBox;
3043	GetBoundingBox(boundingBox);
3044
3045	// no intersections with bounding box
3046	if (!Overlap(box, boundingBox))
3047	{
3048	return 1;
3049	}
3050
3051	// box cotains bounding box of geometry >=> contains geometry
3052	if (box.Includes(boundingBox))
3053	return -1;
3054
3055	int result = 0;
3056
3057	// test geometry planes for intersections
3058	vector<Plane3>::const_iterator it, it_end = mPlanes.end();
3059
3060	for (it = mPlanes.begin(); it != it_end; ++ it)
3061	{
3062	const int side = box.Side(*it);
3063
3064	// box does not intersects geometry
3065	if (side == 1)
3066	{
3067	return 1;
3068	}
3069	//if (side == 0) result = 0;
3070	}
3071
3072	return result;
3073	}
3074
3075
3076	Vector3 BspNodeGeometry::CenterOfMass() const
3077	{
3078	int n = 0;
3079
3080	Vector3 center(0,0,0);
3081
3082	PolygonContainer::const_iterator pit, pit_end = mPolys.end();
3083
3084	for (pit = mPolys.begin(); pit != pit_end; ++ pit)
3085	{
3086	Polygon3 poly = pit;
3087
3088	VertexContainer::const_iterator vit, vit_end = poly->mVertices.end();
3089
3090	for(vit = poly->mVertices.begin(); vit != vit_end; ++ vit)
3091	{
3092	center += *vit;
3093	++ n;
3094	}
3095	}
3096
3097	//Debug << "center: " << center << " new " << center / (float)n << endl;
3098
3099	return center / (float)n;
3100	}
3101
3102
3103	bool BspNodeGeometry::Valid() const
3104	{
3105	if (mPolys.size() < 4)
3106	return false;
3107
3108	return true;
3109	}
3110
3111	void IncludeNodeGeomInMesh(const BspNodeGeometry &geom, Mesh &mesh)
3112	{
3113	// add single polygons to mesh
3114	PolygonContainer::const_iterator it, it_end = geom.mPolys.end();
3115
3116	for (it = geom.mPolys.begin(); it != geom.mPolys.end(); ++ it)
3117	{
3118	Polygon3 poly = (it);
3119	IncludePolyInMesh(*poly, mesh);
3120	}
3121	}
3122
3123
3124	bool BspNodeGeometry::SplitGeometry(BspNodeGeometry &front,
3125	BspNodeGeometry &back,
3126	const Plane3 &splitPlane,
3127	const AxisAlignedBox3 &box,
3128	const float epsilon) const
3129	{
3130	//-- trivial cases
3131	if (0)
3132	{
3133	const int cf = Side(splitPlane, epsilon);
3134
3135	if (cf == -1)
3136	{
3137	back = *this;
3138	return false;
3139	}
3140	else if (cf == 1)
3141	{
3142	front = *this;
3143	return false;
3144	}
3145	}
3146
3147	// get cross section of new polygon
3148	Polygon3 *planePoly = box.CrossSection(splitPlane);
3149
3150	// split polygon with all other polygons
3151	planePoly = SplitPolygon(planePoly, epsilon);
3152
3153	bool splitsGeom = (planePoly != NULL);
3154
3155	//-- new polygon splits all other polygons
3156	for (int i = 0; i < (int)mPolys.size()/* && planePoly*/; ++ i)
3157	{
3158	/// don't use epsilon here to get exact split planes
3159	const int cf =
3160	mPolys[i]->ClassifyPlane(splitPlane, epsilon);
3161
3162	switch (cf)
3163	{
3164	case Polygon3::SPLIT:
3165	{
3166	Polygon3 *poly = new Polygon3(mPolys[i]->mVertices);
3167
3168	Polygon3 *frontPoly = new Polygon3();
3169	Polygon3 *backPoly = new Polygon3();
3170
3171	poly->Split(splitPlane,
3172	*frontPoly,
3173	*backPoly,
3174	epsilon);
3175
3176	DEL_PTR(poly);
3177
3178	if (frontPoly->Valid(epsilon))
3179	{
3180	front.Add(frontPoly, mPlanes[i]);
3181	}
3182	else
3183	{
3184	//Debug << "no f! " << endl;
3185	DEL_PTR(frontPoly);
3186	}
3187
3188	if (backPoly->Valid(epsilon))
3189	{
3190	back.Add(backPoly, mPlanes[i]);
3191	}
3192	else
3193	{
3194	//Debug << "no b! " << endl;
3195	DEL_PTR(backPoly);
3196	}
3197	}
3198
3199	break;
3200	case Polygon3::BACK_SIDE:
3201	back.Add(new Polygon3(mPolys[i]->mVertices), mPlanes[i]);
3202	break;
3203	case Polygon3::FRONT_SIDE:
3204	front.Add(new Polygon3(mPolys[i]->mVertices), mPlanes[i]);
3205	break;
3206	// only put into back container (split should have no effect ...)
3207	case Polygon3::COINCIDENT:
3208	//Debug << "error should not come here" << endl;
3209	splitsGeom = false;
3210
3211	if (DotProd(mPlanes[i].mNormal, splitPlane.mNormal > 0))
3212	back.Add(new Polygon3(mPolys[i]->mVertices), mPlanes[i]);
3213	else
3214	front.Add(new Polygon3(mPolys[i]->mVertices), mPlanes[i]);
3215	break;
3216	default:
3217	break;
3218	}
3219	}
3220
3221	//-- finally add the new polygon to the child node geometries
3222	if (planePoly)
3223	{
3224	// add polygon with reverse orientation to front cell
3225	Plane3 reversePlane(splitPlane);
3226	reversePlane.ReverseOrientation();
3227
3228	// add polygon with normal pointing into positive half space to back cell
3229	back.Add(planePoly, splitPlane);
3230	//back.mPolys.push_back(planePoly);
3231
3232	Polygon3 *reversePoly = planePoly->CreateReversePolygon();
3233	front.Add(reversePoly, reversePlane);
3234	//Debug << "poly normal : " << reversePoly->GetSupportingPlane().mNormal << " split plane normal " << reversePlane.mNormal << endl;
3235	}
3236
3237
3238	return splitsGeom;
3239	}
3240
3241
3242	Polygon3 BspNodeGeometry::SplitPolygon(Polygon3 planePoly,
3243	const float epsilon) const
3244	{
3245	if (!planePoly->Valid(epsilon))
3246	{
3247	//Debug << "not valid!!" << endl;
3248	DEL_PTR(planePoly);
3249	}
3250	// polygon is split by all other planes
3251	for (int i = 0; (i < (int)mPolys.size()) && planePoly; ++ i)
3252	{
3253	//Plane3 plane = mPolys[i]->GetSupportingPlane();
3254	Plane3 plane = mPlanes[i];
3255
3256	/// don't use epsilon here to get exact split planes
3257	const int cf =
3258	planePoly->ClassifyPlane(plane, epsilon);
3259
3260	// split new polygon with all previous planes
3261	switch (cf)
3262	{
3263	case Polygon3::SPLIT:
3264	{
3265	Polygon3 *frontPoly = new Polygon3();
3266	Polygon3 *backPoly = new Polygon3();
3267
3268	planePoly->Split(plane,
3269	*frontPoly,
3270	*backPoly,
3271	epsilon);
3272
3273	// don't need anymore
3274	DEL_PTR(planePoly);
3275	DEL_PTR(frontPoly);
3276
3277	// back polygon is belonging to geometry
3278	if (backPoly->Valid(epsilon))
3279	planePoly = backPoly;
3280	else
3281	DEL_PTR(backPoly);
3282	}
3283	break;
3284	case Polygon3::FRONT_SIDE:
3285	DEL_PTR(planePoly);
3286	break;
3287	// polygon is taken as it is
3288	case Polygon3::BACK_SIDE:
3289	case Polygon3::COINCIDENT:
3290	default:
3291	break;
3292	}
3293	}
3294
3295	return planePoly;
3296	}
3297
3298
3299	ViewCell *BspTree::GetViewCell(const Vector3 &point)
3300	{
3301	if (mRoot == NULL)
3302	return NULL;
3303
3304
3305	stack<BspNode *> nodeStack;
3306	nodeStack.push(mRoot);
3307
3308	ViewCellLeaf *viewcell = NULL;
3309
3310	while (!nodeStack.empty()) {
3311	BspNode *node = nodeStack.top();
3312	nodeStack.pop();
3313
3314	if (node->IsLeaf()) {
3315	viewcell = dynamic_cast<BspLeaf *>(node)->mViewCell;
3316	break;
3317	} else {
3318
3319	BspInterior interior = dynamic_cast<BspInterior >(node);
3320
3321	// random decision
3322	if (interior->GetPlane().Side(point) < 0)
3323	nodeStack.push(interior->GetBack());
3324	else
3325	nodeStack.push(interior->GetFront());
3326	}
3327	}
3328
3329	return viewcell;
3330	}
3331
3332
3333	bool BspTree::Export(ofstream &stream)
3334	{
3335	ExportNode(mRoot, stream);
3336
3337	return true;
3338	}
3339
3340
3341	void BspTree::ExportNode(BspNode *node, ofstream &stream)
3342	{
3343	if (node->IsLeaf())
3344	{
3345	BspLeaf leaf = dynamic_cast<BspLeaf >(node);
3346
3347	int id = -1;
3348	if (leaf->GetViewCell() != mOutOfBoundsCell)
3349	id = leaf->GetViewCell()->GetId();
3350
3351	stream << "<Leaf viewCellId=\"" << id << "\" />" << endl;
3352	}
3353	else
3354	{
3355	BspInterior interior = dynamic_cast<BspInterior >(node);
3356
3357	Plane3 plane = interior->GetPlane();
3358	stream << "<Interior plane=\"" << plane.mNormal.x << " "
3359	<< plane.mNormal.y << " " << plane.mNormal.z << " "
3360	<< plane.mD << "\">" << endl;
3361
3362	ExportNode(interior->GetBack(), stream);
3363	ExportNode(interior->GetFront(), stream);
3364
3365	stream << "</Interior>" << endl;
3366	}
3367	}
3368
3369	}

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