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source: trunk/VUT/GtpVisibilityPreprocessor/src/ViewCellBsp.cpp @ 590

Revision 590, 75.0 KB checked in by mattausch, 18 years ago (diff)
implemented some code for merge history loading

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

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