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source: trunk/VUT/GtpVisibilityPreprocessor/src/ViewCellBsp.cpp @ 442

Revision 442, 62.2 KB checked in by mattausch, 19 years ago (diff)

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1	#include "Plane3.h"
2	#include "ViewCellBsp.h"
3	#include "Mesh.h"
4	#include "common.h"
5	#include "ViewCell.h"
6	#include "Environment.h"
7	#include "Polygon3.h"
8	#include "Ray.h"
9	#include "AxisAlignedBox3.h"
10	#include <stack>
11	#include <time.h>
12	#include <iomanip>
13	#include "Exporter.h"
14	#include "Plane3.h"
15
16	//-- static members
17
18	int BspNode::sMailId = 1;
19
20	/** Evaluates split plane classification with respect to the plane's
21	contribution for a minimum number splits in the tree.
22	*/
23	const float BspTree::sLeastPolySplitsTable[] = {0, 0, 1, 0};
24	/** Evaluates split plane classification with respect to the plane's
25	contribution for a balanced tree.
26	*/
27	const float BspTree::sBalancedPolysTable[] = {1, -1, 0, 0};
28
29	/** Evaluates split plane classification with respect to the plane's
30	contribution for a minimum number of ray splits.
31	*/
32	const float BspTree::sLeastRaySplitsTable[] = {0, 0, 1, 1, 0};
33	/** Evaluates split plane classification with respect to the plane's
34	contribution for balanced rays.
35	*/
36	const float BspTree::sBalancedRaysTable[] = {1, -1, 0, 0, 0};
37
38	int BspTree::sFrontId = 0;
39	int BspTree::sBackId = 0;
40	int BspTree::sFrontAndBackId = 0;
41
42	/****************************************************************/
43	/* class BspNode implementation */
44	/****************************************************************/
45
46	BspNode::BspNode():
47	mParent(NULL)
48	{}
49
50	BspNode::BspNode(BspInterior *parent):
51	mParent(parent)
52	{}
53
54
55	bool BspNode::IsRoot() const
56	{
57	return mParent == NULL;
58	}
59
60	BspInterior *BspNode::GetParent()
61	{
62	return mParent;
63	}
64
65	void BspNode::SetParent(BspInterior *parent)
66	{
67	mParent = parent;
68	}
69
70	/****************************************************************/
71	/* class BspInterior implementation */
72	/****************************************************************/
73
74
75	BspInterior::BspInterior(const Plane3 &plane):
76	mPlane(plane), mFront(NULL), mBack(NULL)
77	{}
78
79	BspInterior::~BspInterior()
80	{
81	DEL_PTR(mFront);
82	DEL_PTR(mBack);
83	}
84
85	bool BspInterior::IsLeaf() const
86	{
87	return false;
88	}
89
90	BspNode *BspInterior::GetBack()
91	{
92	return mBack;
93	}
94
95	BspNode *BspInterior::GetFront()
96	{
97	return mFront;
98	}
99
100	Plane3 *BspInterior::GetPlane()
101	{
102	return &mPlane;
103	}
104
105	void BspInterior::ReplaceChildLink(BspNode oldChild, BspNode newChild)
106	{
107	if (mBack == oldChild)
108	mBack = newChild;
109	else
110	mFront = newChild;
111	}
112
113	void BspInterior::SetupChildLinks(BspNode b, BspNode f)
114	{
115	mBack = b;
116	mFront = f;
117	}
118
119	int BspInterior::SplitPolygons(PolygonContainer &polys,
120	PolygonContainer &frontPolys,
121	PolygonContainer &backPolys,
122	PolygonContainer &coincident)
123	{
124	int splits = 0;
125
126	#ifdef _Debug
127	Debug << "splitting polygons of node " << this << " with plane " << mPlane << endl;
128	#endif
129	while (!polys.empty())
130	{
131	Polygon3 *poly = polys.back();
132	polys.pop_back();
133
134	//Debug << "New polygon with plane: " << poly->GetSupportingPlane() << "\n";
135
136	// classify polygon
137	const int cf = poly->ClassifyPlane(mPlane);
138
139	switch (cf)
140	{
141	case Polygon3::COINCIDENT:
142	coincident.push_back(poly);
143	break;
144	case Polygon3::FRONT_SIDE:
145	frontPolys.push_back(poly);
146	break;
147	case Polygon3::BACK_SIDE:
148	backPolys.push_back(poly);
149	break;
150	case Polygon3::SPLIT:
151	{
152	Polygon3 *front_piece = new Polygon3(poly->mParent);
153	Polygon3 *back_piece = new Polygon3(poly->mParent);
154
155	//-- split polygon into front and back part
156	poly->Split(mPlane, front_piece, back_piece);
157
158	++ splits; // increase number of splits
159
160	//-- inherit rays from parent polygon for blocked ray criterium
161	poly->InheritRays(front_piece, back_piece);
162	//Debug << "p: " << poly->mPiercingRays.size() << " f: " << front_piece->mPiercingRays.size() << " b: " << back_piece->mPiercingRays.size() << endl;
163
164	// check if polygons still valid
165	if (front_piece->Valid())
166	frontPolys.push_back(front_piece);
167	else
168	DEL_PTR(front_piece);
169
170	if (back_piece->Valid())
171	backPolys.push_back(back_piece);
172	else
173	DEL_PTR(back_piece);
174
175	#ifdef _DEBUG
176	Debug << "split " << poly << endl << front_piece << endl << *back_piece << endl;
177	#endif
178	DEL_PTR(poly);
179	}
180	break;
181	default:
182	Debug << "SHOULD NEVER COME HERE\n";
183	break;
184	}
185	}
186
187	return splits;
188	}
189
190	/****************************************************************/
191	/* class BspLeaf implementation */
192	/****************************************************************/
193	BspLeaf::BspLeaf(): mViewCell(NULL)
194	{
195	}
196
197	BspLeaf::BspLeaf(BspViewCell *viewCell):
198	mViewCell(viewCell)
199	{
200	}
201
202	BspLeaf::BspLeaf(BspInterior *parent):
203	BspNode(parent), mViewCell(NULL)
204	{}
205
206	BspLeaf::BspLeaf(BspInterior parent, BspViewCell viewCell):
207	BspNode(parent), mViewCell(viewCell)
208	{
209	}
210
211	BspViewCell *BspLeaf::GetViewCell() const
212	{
213	return mViewCell;
214	}
215
216	void BspLeaf::SetViewCell(BspViewCell *viewCell)
217	{
218	mViewCell = viewCell;
219	}
220
221	bool BspLeaf::IsLeaf() const
222	{
223	return true;
224	}
225
226	void BspLeaf::AddToPvs(const BoundedRayContainer &rays,
227	int &sampleContributions,
228	int &contributingSamples,
229	bool storeLeavesWithRays)
230	{
231	sampleContributions = 0;
232	contributingSamples = 0;
233
234	BoundedRayContainer::const_iterator it, it_end = rays.end();
235
236	// add contributions from samples to the PVS
237	for (it = rays.begin(); it != it_end; ++ it)
238	{
239	int contribution = 0;
240	Ray ray = (it)->mRay;
241
242	if (!ray->intersections.empty())
243	contribution += mViewCell->GetPvs().AddSample(ray->intersections[0].mObject);
244
245	if (ray->sourceObject.mObject)
246	contribution += mViewCell->GetPvs().AddSample(ray->sourceObject.mObject);
247
248	if (contribution > 0)
249	{
250	sampleContributions += contribution;
251	++ contributingSamples;
252	}
253
254	if (storeLeavesWithRays)
255	// warning: intersections not ordered
256	ray->bspIntersections.push_back(Ray::BspIntersection((*it)->mMinT, this));
257	}
258	}
259
260
261	/****************************************************************/
262	/* class BspTree implementation */
263	/****************************************************************/
264
265	BspTree::BspTree():
266	mRoot(NULL),
267	mPvsUseArea(true),
268	mGenerateViewCells(true)
269	{
270	Randomize(); // initialise random generator for heuristics
271
272	// the view cell corresponding to unbounded space
273	mRootCell = new BspViewCell();
274
275	//-- termination criteria for autopartition
276	environment->GetIntValue("BspTree.Termination.maxDepth", mTermMaxDepth);
277	environment->GetIntValue("BspTree.Termination.minPvs", mTermMinPvs);
278	environment->GetIntValue("BspTree.Termination.minPolygons", mTermMinPolys);
279	environment->GetIntValue("BspTree.Termination.minRays", mTermMinRays);
280	environment->GetFloatValue("BspTree.Termination.minArea", mTermMinArea);
281	environment->GetFloatValue("BspTree.Termination.maxRayContribution", mTermMaxRayContribution);
282	environment->GetFloatValue("BspTree.Termination.minAccRayLenght", mTermMinAccRayLength);
283
284	//-- factors for bsp tree split plane heuristics
285	environment->GetFloatValue("BspTree.Factor.verticalSplits", mVerticalSplitsFactor);
286	environment->GetFloatValue("BspTree.Factor.largestPolyArea", mLargestPolyAreaFactor);
287	environment->GetFloatValue("BspTree.Factor.blockedRays", mBlockedRaysFactor);
288	environment->GetFloatValue("BspTree.Factor.leastRaySplits", mLeastRaySplitsFactor);
289	environment->GetFloatValue("BspTree.Factor.balancedRays", mBalancedRaysFactor);
290	environment->GetFloatValue("BspTree.Factor.pvsFactor", mPvsFactor);
291	environment->GetFloatValue("BspTree.Factor.leastSplits" , mLeastSplitsFactor);
292	environment->GetFloatValue("BspTree.Factor.balancedPolys", mBalancedPolysFactor);
293	environment->GetFloatValue("BspTree.Factor.balancedViewCells", mBalancedViewCellsFactor);
294	environment->GetFloatValue("BspTree.Termination.ct_div_ci", mCtDivCi);
295
296	//-- termination criteria for axis aligned split
297	environment->GetFloatValue("BspTree.Termination.AxisAligned.ct_div_ci", mAaCtDivCi);
298	environment->GetFloatValue("BspTree.Termination.AxisAligned.maxCostRatio", mMaxCostRatio);
299	environment->GetIntValue("BspTree.Termination.AxisAligned.minPolys",
300	mTermMinPolysForAxisAligned);
301	environment->GetIntValue("BspTree.Termination.AxisAligned.minRays",
302	mTermMinRaysForAxisAligned);
303	environment->GetIntValue("BspTree.Termination.AxisAligned.minObjects",
304	mTermMinObjectsForAxisAligned);
305	//-- partition criteria
306	environment->GetIntValue("BspTree.maxPolyCandidates", mMaxPolyCandidates);
307	environment->GetIntValue("BspTree.maxRayCandidates", mMaxRayCandidates);
308	environment->GetIntValue("BspTree.splitPlaneStrategy", mSplitPlaneStrategy);
309	environment->GetFloatValue("BspTree.AxisAligned.splitBorder", mSplitBorder);
310	environment->GetIntValue("BspTree.maxTests", mMaxTests);
311
312	environment->GetFloatValue("BspTree.Construction.sideTolerance", Vector3::sDistTolerance);
313	Vector3::sDistToleranceSqrt = Vector3::sDistTolerance * Vector3::sDistTolerance;
314
315
316	Debug << "BSP max depth: " << mTermMaxDepth << endl;
317	Debug << "BSP min PVS: " << mTermMinPvs << endl;
318	Debug << "BSP min area: " << mTermMinArea << endl;
319	Debug << "BSP max polys: " << mTermMinPolys << endl;
320	Debug << "BSP max rays: " << mTermMinRays << endl;
321	Debug << "BSP max polygon candidates: " << mMaxPolyCandidates << endl;
322	Debug << "BSP max plane candidates: " << mMaxRayCandidates << endl;
323
324	Debug << "Split plane strategy: ";
325	if (mSplitPlaneStrategy & RANDOM_POLYGON)
326	Debug << "random polygon ";
327	if (mSplitPlaneStrategy & AXIS_ALIGNED)
328	Debug << "axis aligned ";
329	if (mSplitPlaneStrategy & LEAST_SPLITS)
330	Debug << "least splits ";
331	if (mSplitPlaneStrategy & BALANCED_POLYS)
332	Debug << "balanced polygons ";
333	if (mSplitPlaneStrategy & BALANCED_VIEW_CELLS)
334	Debug << "balanced view cells ";
335	if (mSplitPlaneStrategy & LARGEST_POLY_AREA)
336	Debug << "largest polygon area ";
337	if (mSplitPlaneStrategy & VERTICAL_AXIS)
338	Debug << "vertical axis ";
339	if (mSplitPlaneStrategy & BLOCKED_RAYS)
340	Debug << "blocked rays ";
341	if (mSplitPlaneStrategy & LEAST_RAY_SPLITS)
342	Debug << "least ray splits ";
343	if (mSplitPlaneStrategy & BALANCED_RAYS)
344	Debug << "balanced rays ";
345	if (mSplitPlaneStrategy & PVS)
346	Debug << "pvs";
347
348	Debug << endl;
349	}
350
351	const BspTreeStatistics &BspTree::GetStatistics() const
352	{
353	return mStat;
354	}
355
356	void BspTreeStatistics::Print(ostream &app) const
357	{
358	app << "===== BspTree statistics ===============\n";
359
360	app << setprecision(4);
361
362	app << "#N_CTIME ( Construction time [s] )\n" << Time() << " \n";
363
364	app << "#N_NODES ( Number of nodes )\n" << nodes << "\n";
365
366	app << "#N_INTERIORS ( Number of interior nodes )\n" << Interior() << "\n";
367
368	app << "#N_LEAVES ( Number of leaves )\n" << Leaves() << "\n";
369
370	app << "#N_SPLITS ( Number of splits )\n" << splits << "\n";
371
372	app << "#N_PMAXDEPTHLEAVES ( Percentage of leaves at maximum depth )\n"
373	<< maxDepthNodes * 100 / (double)Leaves() << endl;
374
375	app << "#N_PMAXDEPTHLEAVES ( Percentage of leaves at maximum depth )\n"
376	<< maxDepthNodes * 100 / (double)Leaves() << endl;
377
378	app << "#N_PMINPVSLEAVES ( Percentage of leaves with mininimal PVS )\n"
379	<< minPvsNodes * 100 / (double)Leaves() << endl;
380
381	app << "#N_PMINRAYSLEAVES ( Percentage of leaves with minimal number of rays)\n"
382	<< minRaysNodes * 100 / (double)Leaves() << endl;
383
384	app << "#N_PMINAREALEAVES ( Percentage of leaves with mininum area )\n"
385	<< minAreaNodes * 100 / (double)Leaves() << endl;
386
387	app << "#N_PMAXRAYCONTRIBLEAVES ( Percentage of leaves with maximal ray contribution )\n"
388	<< maxRayContribNodes * 100 / (double)Leaves() << endl;
389
390	app << "#N_PMAXDEPTH ( Maximal reached depth )\n" << maxDepth << endl;
391
392	app << "#N_PMINDEPTH ( Minimal reached depth )\n" << minDepth << endl;
393
394	app << "#AVGDEPTH ( average depth )\n" << AvgDepth() << endl;
395
396	app << "#N_INPUT_POLYGONS (number of input polygons )\n" << polys << endl;
397
398	//app << "#N_PVS: " << pvs << endl;
399
400	app << "#N_ROUTPUT_INPUT_POLYGONS ( ratio polygons after subdivision / input polygons )\n" <<
401	(polys + splits) / (double)polys << endl;
402
403	app << "===== END OF BspTree statistics ==========\n";
404	}
405
406
407	BspTree::~BspTree()
408	{
409	DEL_PTR(mRoot);
410	DEL_PTR(mRootCell);
411	}
412
413	BspViewCell *BspTree::GetRootCell() const
414	{
415	return mRootCell;
416	}
417
418	void BspTree::InsertViewCell(ViewCell *viewCell)
419	{
420	PolygonContainer *polys = new PolygonContainer();
421
422	// don't generate new view cell, insert this one
423	mGenerateViewCells = false;
424	// extract polygons that guide the split process
425	mStat.polys += AddMeshToPolygons(viewCell->GetMesh(), *polys, viewCell);
426	mBox.Include(viewCell->GetBox()); // add to BSP aabb
427
428	InsertPolygons(polys);
429	}
430
431	void BspTree::InsertPolygons(PolygonContainer *polys)
432	{
433	std::stack<BspTraversalData> tStack;
434
435	// traverse existing tree or create new tree
436	if (!mRoot)
437	mRoot = new BspLeaf();
438
439	tStack.push(BspTraversalData(mRoot, polys, 0, mRootCell, new BoundedRayContainer(), 0,
440	mBox.SurfaceArea(), new BspNodeGeometry()));
441
442	while (!tStack.empty())
443	{
444	// filter polygons donw the tree
445	BspTraversalData tData = tStack.top();
446	tStack.pop();
447
448	if (!tData.mNode->IsLeaf())
449	{
450	BspInterior interior = dynamic_cast<BspInterior >(tData.mNode);
451
452	//-- filter view cell polygons down the tree until a leaf is reached
453	if (!tData.mPolygons->empty())
454	{
455	PolygonContainer *frontPolys = new PolygonContainer();
456	PolygonContainer *backPolys = new PolygonContainer();
457	PolygonContainer coincident;
458
459	int splits = 0;
460
461	// split viewcell polygons with respect to split plane
462	splits += interior->SplitPolygons(*tData.mPolygons,
463	*frontPolys,
464	*backPolys,
465	coincident);
466
467	// extract view cells associated with the split polygons
468	ViewCell *frontViewCell = mRootCell;
469	ViewCell *backViewCell = mRootCell;
470
471	BspTraversalData frontData(interior->GetFront(),
472	frontPolys,
473	tData.mDepth + 1,
474	mRootCell,
475	tData.mRays,
476	tData.mPvs,
477	mBox.SurfaceArea(),
478	new BspNodeGeometry());
479
480	BspTraversalData backData(interior->GetBack(),
481	backPolys,
482	tData.mDepth + 1,
483	mRootCell,
484	tData.mRays,
485	tData.mPvs,
486	mBox.SurfaceArea(),
487	new BspNodeGeometry());
488
489	if (!mGenerateViewCells)
490	{
491	ExtractViewCells(frontData,
492	backData,
493	coincident,
494	interior->mPlane);
495	}
496
497	// don't need coincident polygons anymore
498	CLEAR_CONTAINER(coincident);
499
500	mStat.splits += splits;
501
502	// push the children on the stack
503	tStack.push(frontData);
504	tStack.push(backData);
505	}
506
507	// cleanup
508	DEL_PTR(tData.mPolygons);
509	}
510	else
511	{
512	// reached leaf => subdivide current viewcell
513	BspNode *subRoot = Subdivide(tStack, tData);
514	}
515	}
516	}
517
518	int BspTree::AddMeshToPolygons(Mesh mesh, PolygonContainer &polys, MeshInstance parent)
519	{
520	FaceContainer::const_iterator fi;
521
522	// copy the face data to polygons
523	for (fi = mesh->mFaces.begin(); fi != mesh->mFaces.end(); ++ fi)
524	{
525	Polygon3 poly = new Polygon3((fi), mesh);
526
527	if (poly->Valid())
528	{
529	poly->mParent = parent; // set parent intersectable
530	polys.push_back(poly);
531	}
532	else
533	DEL_PTR(poly);
534	}
535	return (int)mesh->mFaces.size();
536	}
537
538	int BspTree::AddToPolygonSoup(const ViewCellContainer &viewCells,
539	PolygonContainer &polys,
540	int maxObjects)
541	{
542	int limit = (maxObjects > 0) ?
543	Min((int)viewCells.size(), maxObjects) : (int)viewCells.size();
544
545	int polysSize = 0;
546
547	for (int i = 0; i < limit; ++ i)
548	{
549	if (viewCells[i]->GetMesh()) // copy the mesh data to polygons
550	{
551	mBox.Include(viewCells[i]->GetBox()); // add to BSP tree aabb
552	polysSize += AddMeshToPolygons(viewCells[i]->GetMesh(), polys, viewCells[i]);
553	}
554	}
555
556	return polysSize;
557	}
558
559	int BspTree::AddToPolygonSoup(const ObjectContainer &objects, PolygonContainer &polys, int maxObjects)
560	{
561	int limit = (maxObjects > 0) ? Min((int)objects.size(), maxObjects) : (int)objects.size();
562
563	for (int i = 0; i < limit; ++i)
564	{
565	Intersectable object = objects[i];//it;
566	Mesh *mesh = NULL;
567
568	switch (object->Type()) // extract the meshes
569	{
570	case Intersectable::MESH_INSTANCE:
571	mesh = dynamic_cast<MeshInstance *>(object)->GetMesh();
572	break;
573	case Intersectable::VIEW_CELL:
574	mesh = dynamic_cast<ViewCell *>(object)->GetMesh();
575	break;
576	// TODO: handle transformed mesh instances
577	default:
578	Debug << "intersectable type not supported" << endl;
579	break;
580	}
581
582	if (mesh) // copy the mesh data to polygons
583	{
584	mBox.Include(object->GetBox()); // add to BSP tree aabb
585	AddMeshToPolygons(mesh, polys, mRootCell);
586	}
587	}
588
589	return (int)polys.size();
590	}
591
592	void BspTree::Construct(const ViewCellContainer &viewCells)
593	{
594	mStat.nodes = 1;
595	mBox.Initialize(); // initialise bsp tree bounding box
596
597	// copy view cell meshes into one big polygon soup
598	PolygonContainer *polys = new PolygonContainer();
599	mStat.polys = AddToPolygonSoup(viewCells, *polys);
600
601	// view cells are given
602	mGenerateViewCells = false;
603	// construct tree from the view cell polygons
604	Construct(polys, new BoundedRayContainer());
605	}
606
607
608	void BspTree::Construct(const ObjectContainer &objects)
609	{
610	mStat.nodes = 1;
611	mBox.Initialize(); // initialise bsp tree bounding box
612
613	PolygonContainer *polys = new PolygonContainer();
614
615	mGenerateViewCells = true;
616	// copy mesh instance polygons into one big polygon soup
617	mStat.polys = AddToPolygonSoup(objects, *polys);
618
619	// construct tree from polygon soup
620	Construct(polys, new BoundedRayContainer());
621	}
622
623	void BspTree::Construct(const RayContainer &sampleRays)
624	{
625	mStat.nodes = 1;
626	mBox.Initialize(); // initialise BSP tree bounding box
627
628	PolygonContainer *polys = new PolygonContainer();
629	BoundedRayContainer *rays = new BoundedRayContainer();
630
631	RayContainer::const_iterator rit, rit_end = sampleRays.end();
632
633	// generate view cells
634	mGenerateViewCells = false;
635
636	long startTime = GetTime();
637
638	Debug << "** Extracting polygons from rays **\n";
639
640	std::map<Face , Polygon3 > facePolyMap;
641
642	//-- extract polygons intersected by the rays
643	for (rit = sampleRays.begin(); rit != rit_end; ++ rit)
644	{
645	Ray ray = rit;
646
647	// get ray-face intersection. Store polygon representing the rays together
648	// with rays intersecting the face.
649	if (!ray->intersections.empty())
650	{
651	MeshInstance obj = dynamic_cast<MeshInstance >(ray->intersections[0].mObject);
652	Face *face = obj->GetMesh()->mFaces[ray->intersections[0].mFace];
653
654	std::map<Face , Polygon3 >::iterator it = facePolyMap.find(face);
655
656	if (it != facePolyMap.end())
657	{
658	//store rays if needed for heuristics
659	if (mSplitPlaneStrategy & BLOCKED_RAYS)
660	(*it).second->mPiercingRays.push_back(ray);
661	}
662	else
663	{ //store rays if needed for heuristics
664	Polygon3 *poly = new Polygon3(face, obj->GetMesh());
665	poly->mParent = obj;
666	polys->push_back(poly);
667
668	if (mSplitPlaneStrategy & BLOCKED_RAYS)
669	poly->mPiercingRays.push_back(ray);
670
671	facePolyMap[face] = poly;
672	}
673	}
674	}
675
676	facePolyMap.clear();
677
678	// compute bounding box
679	Polygon3::IncludeInBox(*polys, mBox);
680
681	//-- store rays
682	for (rit = sampleRays.begin(); rit != rit_end; ++ rit)
683	{
684	Ray ray = rit;
685	ray->SetId(-1); // reset id
686
687	float minT, maxT;
688	if (BoundRay(*ray, minT, maxT))
689	rays->push_back(new BoundedRay(ray, minT, maxT));
690	}
691
692	mStat.polys = (int)polys->size();
693
694	Debug << "** Finished polygon extraction **" << endl;
695	Debug << (int)polys->size() << " polys extracted from " << (int)sampleRays.size() << " rays" << endl;
696	Debug << "extraction time: " << TimeDiff(startTime, GetTime())*1e-3 << "s" << endl;
697
698	Construct(polys, rays);
699	}
700
701	void BspTree::Construct(const ObjectContainer &objects, const RayContainer &sampleRays)
702	{
703	mStat.nodes = 1;
704	mBox.Initialize(); // initialise BSP tree bounding box
705
706	BoundedRayContainer *rays = new BoundedRayContainer();
707	PolygonContainer *polys = new PolygonContainer();
708
709	mGenerateViewCells = true;
710
711	// copy mesh instance polygons into one big polygon soup
712	mStat.polys = AddToPolygonSoup(objects, *polys);
713
714	RayContainer::const_iterator rit, rit_end = sampleRays.end();
715
716	//-- store rays
717	for (rit = sampleRays.begin(); rit != rit_end; ++ rit)
718	{
719	Ray ray = rit;
720	ray->SetId(-1); // reset id
721
722	float minT, maxT;
723	if (BoundRay(*ray, minT, maxT))
724	rays->push_back(new BoundedRay(ray, minT, maxT));
725	}
726
727	Debug << "tree has " << (int)polys->size() << " polys, " << (int)sampleRays.size() << " rays" << endl;
728	Construct(polys, rays);
729	}
730
731	void BspTree::Construct(PolygonContainer polys, BoundedRayContainer rays)
732	{
733	std::stack<BspTraversalData> tStack;
734
735	mRoot = new BspLeaf();
736
737	// constrruct root node geometry
738	BspNodeGeometry *cell = new BspNodeGeometry();
739	ConstructGeometry(mRoot, *cell);
740
741	BspTraversalData tData(mRoot, polys, 0, mRootCell, rays,
742	ComputePvsSize(*rays), cell->GetArea(), cell);
743
744	tStack.push(tData);
745
746	mStat.Start();
747	cout << "Contructing bsp tree ... ";
748	long startTime = GetTime();
749	while (!tStack.empty())
750	{
751	tData = tStack.top();
752
753	tStack.pop();
754
755	// subdivide leaf node
756	BspNode *r = Subdivide(tStack, tData);
757
758	if (r == mRoot)
759	Debug << "BSP tree construction time spent at root: " << TimeDiff(startTime, GetTime())*1e-3 << "s" << endl;
760	}
761
762	cout << "finished\n";
763
764	mStat.Stop();
765	}
766
767	bool BspTree::TerminationCriteriaMet(const BspTraversalData &data) const
768	{
769	return
770	(((int)data.mPolygons->size() <= mTermMinPolys) \|\|
771	((int)data.mRays->size() <= mTermMinRays) \|\|
772	(data.mPvs <= mTermMinPvs) \|\|
773	(data.mArea <= mTermMinArea) \|\|
774	(data.mDepth >= mTermMaxDepth) \|\|
775	(data.GetAvgRayContribution() < mTermMaxRayContribution));
776	}
777
778	BspNode *BspTree::Subdivide(BspTraversalStack &tStack, BspTraversalData &tData)
779	{
780	//-- terminate traversal
781	if (TerminationCriteriaMet(tData))
782	{
783	BspLeaf leaf = dynamic_cast<BspLeaf >(tData.mNode);
784
785	BspViewCell *viewCell;
786
787	// generate new view cell for each leaf
788	if (mGenerateViewCells)
789	{
790	viewCell = new BspViewCell();
791	}
792	else
793	{
794	// add view cell to leaf
795	viewCell = dynamic_cast<BspViewCell *>(tData.mViewCell);
796	}
797
798	leaf->SetViewCell(viewCell);
799	viewCell->mBspLeaves.push_back(leaf);
800
801	//-- add pvs
802	if (viewCell != mRootCell)
803	{
804	int conSamp = 0, sampCon = 0;
805	leaf->AddToPvs(*tData.mRays, conSamp, sampCon);
806
807	mStat.contributingSamples += conSamp;
808	mStat.sampleContributions += sampCon;
809	}
810
811	EvaluateLeafStats(tData);
812
813	//-- clean up
814
815	// discard polygons
816	CLEAR_CONTAINER(*tData.mPolygons);
817	// discard rays
818	CLEAR_CONTAINER(*tData.mRays);
819
820	DEL_PTR(tData.mPolygons);
821	DEL_PTR(tData.mRays);
822
823	return leaf;
824	}
825
826	//-- continue subdivision
827	PolygonContainer coincident;
828
829	BspTraversalData tFrontData(NULL, new PolygonContainer(), tData.mDepth + 1, mRootCell,
830	new BoundedRayContainer(), 0, 0, new BspNodeGeometry());
831	BspTraversalData tBackData(NULL, new PolygonContainer(), tData.mDepth + 1, mRootCell,
832	new BoundedRayContainer(), 0, 0, new BspNodeGeometry());
833
834	// create new interior node and two leaf nodes
835	BspInterior *interior =
836	SubdivideNode(tData, tFrontData, tBackData, coincident);
837
838	#ifdef _DEBUG
839	if (frontPolys->empty() && backPolys->empty() && (coincident.size() > 2))
840	{ for (PolygonContainer::iterator it = coincident.begin(); it != coincident.end(); ++it)
841	Debug << (it) << " " << (it)->GetArea() << " " << (*it)->mParent << endl ;
842	Debug << endl;}
843	#endif
844
845	// extract view cells from coincident polygons according to plane normal
846	// only if front or back polygons are empty
847	if (!mGenerateViewCells)
848	{
849	ExtractViewCells(tFrontData,
850	tBackData,
851	coincident,
852	interior->mPlane);
853	}
854
855	// don't need coincident polygons anymory
856	CLEAR_CONTAINER(coincident);
857
858	// push the children on the stack
859	tStack.push(tFrontData);
860	tStack.push(tBackData);
861
862	// cleanup
863	DEL_PTR(tData.mNode);
864	DEL_PTR(tData.mPolygons);
865	DEL_PTR(tData.mRays);
866	DEL_PTR(tData.mGeometry);
867
868	return interior;
869	}
870
871	void BspTree::ExtractViewCells(BspTraversalData &frontData,
872	BspTraversalData &backData,
873	const PolygonContainer &coincident,
874	const Plane3 &splitPlane) const
875	{
876	// if not empty, tree is further subdivided => don't have to find view cell
877	bool foundFront = !frontData.mPolygons->empty();
878	bool foundBack = !frontData.mPolygons->empty();
879
880	PolygonContainer::const_iterator it =
881	coincident.begin(), it_end = coincident.end();
882
883	//-- find first view cells in front and back leafs
884	for (; !(foundFront && foundBack) && (it != it_end); ++ it)
885	{
886	if (DotProd((*it)->GetNormal(), splitPlane.mNormal) > 0)
887	{
888	backData.mViewCell = dynamic_cast<ViewCell >((it)->mParent);
889	foundBack = true;
890	}
891	else
892	{
893	frontData.mViewCell = dynamic_cast<ViewCell >((it)->mParent);
894	foundFront = true;
895	}
896	}
897	}
898
899	BspInterior *BspTree::SubdivideNode(BspTraversalData &tData,
900	BspTraversalData &frontData,
901	BspTraversalData &backData,
902	PolygonContainer &coincident)
903	{
904	mStat.nodes += 2;
905
906	BspLeaf leaf = dynamic_cast<BspLeaf >(tData.mNode);
907
908	Debug << "*********************" << endl;
909	long startTime = GetTime();
910
911	// select subdivision plane
912	BspInterior *interior =
913	new BspInterior(SelectPlane(leaf, tData));
914	Debug << "time used for split plane selection: " << TimeDiff(startTime, GetTime())*1e-3 << "s" << endl;
915	#ifdef _DEBUG
916	Debug << interior << endl;
917	#endif
918
919
920	Debug << "number of rays: " << tData.mRays->size() << endl;
921	Debug << "number of polys: " << tData.mPolygons->size() << endl;
922
923	startTime = GetTime();
924
925	// subdivide rays into front and back rays
926	SplitRays(interior->mPlane, tData.mRays, frontData.mRays, *backData.mRays);
927
928	Debug << "time used for rays splitting: " << TimeDiff(startTime, GetTime())*1e-3 << "s" << endl;
929
930	startTime = GetTime();
931	// subdivide polygons with plane
932	mStat.splits += interior->SplitPolygons(*tData.mPolygons,
933	*frontData.mPolygons,
934	*backData.mPolygons,
935	coincident);
936
937	Debug << "time used for polygon splitting: " << TimeDiff(startTime, GetTime())*1e-3 << "s" << endl;
938
939	// compute pvs
940	frontData.mPvs = ComputePvsSize(*frontData.mRays);
941	backData.mPvs = ComputePvsSize(*backData.mRays);
942
943	// split geometry and compute area
944	if (1)
945	{
946	tData.mGeometry->SplitGeometry(*frontData.mGeometry,
947	*backData.mGeometry,
948	*this,
949	interior->mPlane);
950
951
952	frontData.mArea = frontData.mGeometry->GetArea();
953	backData.mArea = backData.mGeometry->GetArea();
954	}
955
956	// compute accumulated ray length
957	//frontData.mAccRayLength = AccumulatedRayLength(*frontData.mRays);
958	//backData.mAccRayLength = AccumulatedRayLength(*backData.mRays);
959
960	//-- create front and back leaf
961
962	BspInterior *parent = leaf->GetParent();
963
964	// replace a link from node's parent
965	if (!leaf->IsRoot())
966	{
967	parent->ReplaceChildLink(leaf, interior);
968	interior->SetParent(parent);
969	}
970	else // new root
971	{
972	mRoot = interior;
973	}
974
975	// and setup child links
976	interior->SetupChildLinks(new BspLeaf(interior), new BspLeaf(interior));
977
978	frontData.mNode = interior->mFront;
979	backData.mNode = interior->mBack;
980
981	//DEL_PTR(leaf);
982	return interior;
983	}
984
985	void BspTree::SortSplitCandidates(const PolygonContainer &polys,
986	const int axis,
987	vector<SortableEntry> &splitCandidates) const
988	{
989	splitCandidates.clear();
990
991	int requestedSize = 2 * (int)polys.size();
992	// creates a sorted split candidates array
993	splitCandidates.reserve(requestedSize);
994
995	PolygonContainer::const_iterator it, it_end = polys.end();
996
997	AxisAlignedBox3 box;
998
999	// insert all queries
1000	for(it = polys.begin(); it != it_end; ++ it)
1001	{
1002	box.Initialize();
1003	box.Include((it));
1004
1005	splitCandidates.push_back(SortableEntry(SortableEntry::POLY_MIN, box.Min(axis), *it));
1006	splitCandidates.push_back(SortableEntry(SortableEntry::POLY_MAX, box.Max(axis), *it));
1007	}
1008
1009	stable_sort(splitCandidates.begin(), splitCandidates.end());
1010	}
1011
1012
1013	float BspTree::BestCostRatio(const PolygonContainer &polys,
1014	const AxisAlignedBox3 &box,
1015	const int axis,
1016	float &position,
1017	int &objectsBack,
1018	int &objectsFront) const
1019	{
1020	vector<SortableEntry> splitCandidates;
1021
1022	SortSplitCandidates(polys, axis, splitCandidates);
1023
1024	// go through the lists, count the number of objects left and right
1025	// and evaluate the following cost funcion:
1026	// C = ct_div_ci + (ol + or)/queries
1027
1028	int objectsLeft = 0, objectsRight = (int)polys.size();
1029
1030	float minBox = box.Min(axis);
1031	float maxBox = box.Max(axis);
1032	float boxArea = box.SurfaceArea();
1033
1034	float minBand = minBox + mSplitBorder * (maxBox - minBox);
1035	float maxBand = minBox + (1.0f - mSplitBorder) * (maxBox - minBox);
1036
1037	float minSum = 1e20f;
1038	vector<SortableEntry>::const_iterator ci, ci_end = splitCandidates.end();
1039
1040	for(ci = splitCandidates.begin(); ci != ci_end; ++ ci)
1041	{
1042	switch ((*ci).type)
1043	{
1044	case SortableEntry::POLY_MIN:
1045	++ objectsLeft;
1046	break;
1047	case SortableEntry::POLY_MAX:
1048	-- objectsRight;
1049	break;
1050	default:
1051	break;
1052	}
1053
1054	if ((ci).value > minBand && (ci).value < maxBand)
1055	{
1056	AxisAlignedBox3 lbox = box;
1057	AxisAlignedBox3 rbox = box;
1058	lbox.SetMax(axis, (*ci).value);
1059	rbox.SetMin(axis, (*ci).value);
1060
1061	float sum = objectsLeft * lbox.SurfaceArea() +
1062	objectsRight * rbox.SurfaceArea();
1063
1064	if (sum < minSum)
1065	{
1066	minSum = sum;
1067	position = (*ci).value;
1068
1069	objectsBack = objectsLeft;
1070	objectsFront = objectsRight;
1071	}
1072	}
1073	}
1074
1075	float oldCost = (float)polys.size();
1076	float newCost = mAaCtDivCi + minSum / boxArea;
1077	float ratio = newCost / oldCost;
1078
1079
1080	#if 0
1081	Debug << "====================" << endl;
1082	Debug << "costRatio=" << ratio << " pos=" << position<<" t=" << (position - minBox)/(maxBox - minBox)
1083	<< "\t o=(" << objectsBack << "," << objectsFront << ")" << endl;
1084	#endif
1085	return ratio;
1086	}
1087
1088	bool BspTree::SelectAxisAlignedPlane(Plane3 &plane,
1089	const PolygonContainer &polys) const
1090	{
1091	AxisAlignedBox3 box;
1092	box.Initialize();
1093
1094	// create bounding box of region
1095	Polygon3::IncludeInBox(polys, box);
1096
1097	int objectsBack = 0, objectsFront = 0;
1098	int axis = 0;
1099	float costRatio = MAX_FLOAT;
1100	Vector3 position;
1101
1102	//-- area subdivision
1103	for (int i = 0; i < 3; ++ i)
1104	{
1105	float p = 0;
1106	float r = BestCostRatio(polys, box, i, p, objectsBack, objectsFront);
1107
1108	if (r < costRatio)
1109	{
1110	costRatio = r;
1111	axis = i;
1112	position = p;
1113	}
1114	}
1115
1116	if (costRatio >= mMaxCostRatio)
1117	return false;
1118
1119	Vector3 norm(0,0,0); norm[axis] = 1.0f;
1120	plane = Plane3(norm, position);
1121
1122	return true;
1123	}
1124
1125	Plane3 BspTree::SelectPlane(BspLeaf *leaf, BspTraversalData &data)
1126	{
1127	if (data.mPolygons->empty() && data.mRays->empty())
1128	{
1129	Debug << "Warning: No autopartition polygon candidate available\n";
1130
1131	// return axis aligned split
1132	AxisAlignedBox3 box;
1133	box.Initialize();
1134
1135	// create bounding box of region
1136	Polygon3::IncludeInBox(*data.mPolygons, box);
1137
1138	const int axis = box.Size().DrivingAxis();
1139	const Vector3 position = (box.Min()[axis] + box.Max()[axis])*0.5f;
1140
1141	Vector3 norm(0,0,0); norm[axis] = 1.0f;
1142	return Plane3(norm, position);
1143	}
1144
1145	if ((mSplitPlaneStrategy & AXIS_ALIGNED) &&
1146	((int)data.mPolygons->size() > mTermMinPolysForAxisAligned) &&
1147	((int)data.mRays->size() > mTermMinRaysForAxisAligned) &&
1148	((mTermMinObjectsForAxisAligned < 0) \|\|
1149	(Polygon3::ParentObjectsSize(*data.mPolygons) > mTermMinObjectsForAxisAligned)))
1150	{
1151	Plane3 plane;
1152	if (SelectAxisAlignedPlane(plane, *data.mPolygons))
1153	return plane;
1154	}
1155
1156	// simplest strategy: just take next polygon
1157	if (mSplitPlaneStrategy & RANDOM_POLYGON)
1158	{
1159	if (!data.mPolygons->empty())
1160	{
1161	Polygon3 nextPoly = (data.mPolygons)[Random((int)data.mPolygons->size())];
1162	return nextPoly->GetSupportingPlane();
1163	}
1164	else
1165	{
1166	const int candidateIdx = Random((int)data.mRays->size());
1167	BoundedRay bRay = (data.mRays)[candidateIdx];
1168
1169	Ray *ray = bRay->mRay;
1170
1171	const Vector3 minPt = ray->Extrap(bRay->mMinT);
1172	const Vector3 maxPt = ray->Extrap(bRay->mMaxT);
1173
1174	const Vector3 pt = (maxPt + minPt) * 0.5;
1175
1176	const Vector3 normal = ray->GetDir();
1177
1178	return Plane3(normal, pt);
1179	}
1180
1181	return Plane3();
1182	}
1183
1184	// use heuristics to find appropriate plane
1185	return SelectPlaneHeuristics(leaf, data);
1186	}
1187
1188	Plane3 BspTree::SelectPlaneHeuristics(BspLeaf *leaf, BspTraversalData &data)
1189	{
1190	float lowestCost = MAX_FLOAT;
1191	Plane3 bestPlane;
1192	Plane3 plane;
1193
1194	int limit = Min((int)data.mPolygons->size(), mMaxPolyCandidates);
1195
1196	int candidateIdx = limit;
1197
1198	for (int i = 0; i < limit; ++ i)
1199	{
1200	candidateIdx = GetNextCandidateIdx(candidateIdx, *data.mPolygons);
1201
1202	Polygon3 poly = (data.mPolygons)[candidateIdx];
1203	// evaluate current candidate
1204	const float candidateCost =
1205	SplitPlaneCost(poly->GetSupportingPlane(), data);
1206
1207	if (candidateCost < lowestCost)
1208	{
1209	bestPlane = poly->GetSupportingPlane();
1210	lowestCost = candidateCost;
1211	}
1212	}
1213
1214	//Debug << "lowest: " << lowestCost << endl;
1215
1216	//-- choose candidate planes extracted from rays
1217	// we currently use two methods
1218	// 1) take 3 ray endpoints, where two are minimum and one a maximum
1219	// point or the other way round
1220	// 2) take plane normal as plane normal and the midpoint of the ray.
1221	// PROBLEM: does not resemble any point where visibility is likely to change
1222	const BoundedRayContainer *rays = data.mRays;
1223
1224	for (int i = 0; i < mMaxRayCandidates / 2; ++ i)
1225	{
1226	candidateIdx = Random((int)rays->size());
1227	BoundedRay bRay = (rays)[candidateIdx];
1228
1229	Ray *ray = bRay->mRay;
1230
1231	const Vector3 minPt = ray->Extrap(bRay->mMinT);
1232	const Vector3 maxPt = ray->Extrap(bRay->mMaxT);
1233
1234	const Vector3 pt = (maxPt + minPt) * 0.5;
1235
1236	const Vector3 normal = ray->GetDir();
1237
1238	plane = Plane3(normal, pt);
1239
1240	const float candidateCost = SplitPlaneCost(plane, data);
1241
1242	if (candidateCost < lowestCost)
1243	{
1244	bestPlane = plane;
1245
1246	lowestCost = candidateCost;
1247	}
1248	}
1249
1250	//Debug << "lowest: " << lowestCost << endl;
1251	for (int i = 0; i < mMaxRayCandidates / 2; ++ i)
1252	{
1253	Vector3 pt[3];
1254	int idx[3];
1255	int cmaxT = 0;
1256	int cminT = 0;
1257	bool chooseMin = false;
1258
1259	for (int j = 0; j < 3; j ++)
1260	{
1261	idx[j] = Random((int)rays->size() * 2);
1262
1263	if (idx[j] >= (int)rays->size())
1264	{
1265	idx[j] -= (int)rays->size();
1266
1267	chooseMin = (cminT < 2);
1268	}
1269	else
1270	chooseMin = (cmaxT < 2);
1271
1272	BoundedRay bRay = (rays)[idx[j]];
1273	pt[j] = chooseMin ? bRay->mRay->Extrap(bRay->mMinT) : bRay->mRay->Extrap(bRay->mMaxT);
1274	}
1275
1276	plane = Plane3(pt[0], pt[1], pt[2]);
1277
1278	const float candidateCost = SplitPlaneCost(plane, data);
1279
1280	if (candidateCost < lowestCost)
1281	{
1282	//Debug << "choose ray plane 2: " << candidateCost << endl;
1283	bestPlane = plane;
1284
1285	lowestCost = candidateCost;
1286	}
1287	}
1288
1289	#ifdef _DEBUG
1290	Debug << "plane lowest cost: " << lowestCost << endl;
1291	#endif
1292	return bestPlane;
1293	}
1294
1295	int BspTree::GetNextCandidateIdx(int currentIdx, PolygonContainer &polys)
1296	{
1297	const int candidateIdx = Random(currentIdx --);
1298
1299	// swap candidates to avoid testing same plane 2 times
1300	std::swap(polys[currentIdx], polys[candidateIdx]);
1301
1302	return currentIdx;
1303	//return Random((int)polys.size());
1304	}
1305
1306	float BspTree::SplitPlaneCost(const Plane3 &candidatePlane,
1307	const PolygonContainer &polys) const
1308	{
1309	float val = 0;
1310
1311	float sumBalancedPolys = 0;
1312	float sumSplits = 0;
1313	float sumPolyArea = 0;
1314	float sumBalancedViewCells = 0;
1315	float sumBlockedRays = 0;
1316	float totalBlockedRays = 0;
1317	//float totalArea = 0;
1318	int totalViewCells = 0;
1319
1320	// need three unique ids for each type of view cell
1321	// for balanced view cells criterium
1322	ViewCell::NewMail();
1323	const int backId = ViewCell::sMailId;
1324	ViewCell::NewMail();
1325	const int frontId = ViewCell::sMailId;
1326	ViewCell::NewMail();
1327	const int frontAndBackId = ViewCell::sMailId;
1328
1329	bool useRand;;
1330	int limit;
1331
1332	// choose test polyongs randomly if over threshold
1333	if ((int)polys.size() > mMaxTests)
1334	{
1335	useRand = true;
1336	limit = mMaxTests;
1337	}
1338	else
1339	{
1340	useRand = false;
1341	limit = (int)polys.size();
1342	}
1343
1344
1345	for (int i = 0; i < limit; ++ i)
1346	{
1347	const int testIdx = useRand ? Random(limit) : i;
1348
1349	Polygon3 *poly = polys[testIdx];
1350
1351	const int classification = poly->ClassifyPlane(candidatePlane);
1352
1353	if (mSplitPlaneStrategy & BALANCED_POLYS)
1354	sumBalancedPolys += sBalancedPolysTable[classification];
1355
1356	if (mSplitPlaneStrategy & LEAST_SPLITS)
1357	sumSplits += sLeastPolySplitsTable[classification];
1358
1359	if (mSplitPlaneStrategy & LARGEST_POLY_AREA)
1360	{
1361	if (classification == Polygon3::COINCIDENT)
1362	sumPolyArea += poly->GetArea();
1363	//totalArea += area;
1364	}
1365
1366	if (mSplitPlaneStrategy & BLOCKED_RAYS)
1367	{
1368	const float blockedRays = (float)poly->mPiercingRays.size();
1369
1370	if (classification == Polygon3::COINCIDENT)
1371	sumBlockedRays += blockedRays;
1372
1373	totalBlockedRays += blockedRays;
1374	}
1375
1376	// assign view cells to back or front according to classificaion
1377	if (mSplitPlaneStrategy & BALANCED_VIEW_CELLS)
1378	{
1379	MeshInstance *viewCell = poly->mParent;
1380
1381	// assure that we only count a view cell
1382	// once for the front and once for the back side of the plane
1383	if (classification == Polygon3::FRONT_SIDE)
1384	{
1385	if ((viewCell->mMailbox != frontId) &&
1386	(viewCell->mMailbox != frontAndBackId))
1387	{
1388	sumBalancedViewCells += 1.0;
1389
1390	if (viewCell->mMailbox != backId)
1391	viewCell->mMailbox = frontId;
1392	else
1393	viewCell->mMailbox = frontAndBackId;
1394
1395	++ totalViewCells;
1396	}
1397	}
1398	else if (classification == Polygon3::BACK_SIDE)
1399	{
1400	if ((viewCell->mMailbox != backId) &&
1401	(viewCell->mMailbox != frontAndBackId))
1402	{
1403	sumBalancedViewCells -= 1.0;
1404
1405	if (viewCell->mMailbox != frontId)
1406	viewCell->mMailbox = backId;
1407	else
1408	viewCell->mMailbox = frontAndBackId;
1409
1410	++ totalViewCells;
1411	}
1412	}
1413	}
1414	}
1415
1416	const float polysSize = (float)polys.size() + Limits::Small;
1417
1418	// all values should be approx. between 0 and 1 so they can be combined
1419	// and scaled with the factors according to their importance
1420	if (mSplitPlaneStrategy & BALANCED_POLYS)
1421	val += mBalancedPolysFactor * fabs(sumBalancedPolys) / polysSize;
1422
1423	if (mSplitPlaneStrategy & LEAST_SPLITS)
1424	val += mLeastSplitsFactor * sumSplits / polysSize;
1425
1426	if (mSplitPlaneStrategy & LARGEST_POLY_AREA)
1427	// HACK: polys.size should be total area so scaling is between 0 and 1
1428	val += mLargestPolyAreaFactor * (float)polys.size() / sumPolyArea;
1429
1430	if (mSplitPlaneStrategy & BLOCKED_RAYS)
1431	if (totalBlockedRays != 0)
1432	val += mBlockedRaysFactor * (totalBlockedRays - sumBlockedRays) / totalBlockedRays;
1433
1434	if (mSplitPlaneStrategy & BALANCED_VIEW_CELLS)
1435	val += mBalancedViewCellsFactor * fabs(sumBalancedViewCells) /
1436	((float)totalViewCells + Limits::Small);
1437
1438	return val;
1439	}
1440
1441	bool BspTree::BoundRay(const Ray &ray, float &minT, float &maxT) const
1442	{
1443	maxT = 1e6;
1444	minT = 0;
1445
1446	// test with tree bounding box
1447	if (!mBox.GetMinMaxT(ray, &minT, &maxT))
1448	return false;
1449
1450	if (minT < 0) // start ray from origin
1451	minT = 0;
1452
1453	// bound ray or line segment
1454	if ((ray.GetType() == Ray::LOCAL_RAY) &&
1455	!ray.intersections.empty() &&
1456	(ray.intersections[0].mT <= maxT))
1457	{
1458	maxT = ray.intersections[0].mT;
1459	}
1460
1461	return true;
1462	}
1463
1464	inline void BspTree::GenerateUniqueIdsForPvs()
1465	{
1466	Intersectable::NewMail(); sBackId = ViewCell::sMailId;
1467	Intersectable::NewMail(); sFrontId = ViewCell::sMailId;
1468	Intersectable::NewMail(); sFrontAndBackId = ViewCell::sMailId;
1469	}
1470
1471	float BspTree::SplitPlaneCost(const Plane3 &candidatePlane,
1472	const BoundedRayContainer &rays,
1473	const int pvs,
1474	const float area,
1475	const BspNodeGeometry &cell) const
1476	{
1477	float val = 0;
1478
1479	float sumBalancedRays = 0;
1480	float sumRaySplits = 0;
1481
1482	int frontPvs = 0;
1483	int backPvs = 0;
1484
1485	// probability that view point lies in child
1486	float pOverall = 0;
1487	float pFront = 0;
1488	float pBack = 0;
1489
1490	const bool pvsUseLen = false;
1491
1492	if (mSplitPlaneStrategy & PVS)
1493	{
1494	// create unique ids for pvs heuristics
1495	GenerateUniqueIdsForPvs();
1496
1497	if (mPvsUseArea) // use front and back cell areas to approximate volume
1498	{
1499	// construct child geometry with regard to the candidate split plane
1500	BspNodeGeometry frontCell;
1501	BspNodeGeometry backCell;
1502
1503	cell.SplitGeometry(frontCell, backCell, *this, candidatePlane);
1504
1505	pFront = frontCell.GetArea();
1506	pBack = backCell.GetArea();
1507
1508	pOverall = area;
1509	}
1510	}
1511
1512	bool useRand;;
1513	int limit;
1514
1515	// choose test polyongs randomly if over threshold
1516	if ((int)rays.size() > mMaxTests)
1517	{
1518	useRand = true;
1519	limit = mMaxTests;
1520	}
1521	else
1522	{
1523	useRand = false;
1524	limit = (int)rays.size();
1525	}
1526
1527	for (int i = 0; i < limit; ++ i)
1528	{
1529	const int testIdx = useRand ? Random(limit) : i;
1530
1531	BoundedRay *bRay = rays[testIdx];
1532
1533	Ray *ray = bRay->mRay;
1534	const float minT = bRay->mMinT;
1535	const float maxT = bRay->mMaxT;
1536
1537	Vector3 entP, extP;
1538
1539	const int cf =
1540	ray->ClassifyPlane(candidatePlane, minT, maxT, entP, extP);
1541
1542	if (mSplitPlaneStrategy & LEAST_RAY_SPLITS)
1543	{
1544	sumBalancedRays += sBalancedRaysTable[cf];
1545	}
1546
1547	if (mSplitPlaneStrategy & BALANCED_RAYS)
1548	{
1549	sumRaySplits += sLeastRaySplitsTable[cf];
1550	}
1551
1552	if (mSplitPlaneStrategy & PVS)
1553	{
1554	// in case the ray intersects an object
1555	// assure that we only count the object
1556	// once for the front and once for the back side of the plane
1557
1558	// add the termination object
1559	if (!ray->intersections.empty())
1560	AddObjToPvs(ray->intersections[0].mObject, cf, frontPvs, backPvs);
1561
1562	// add the source object
1563	AddObjToPvs(ray->sourceObject.mObject, cf, frontPvs, backPvs);
1564
1565	if (mPvsUseArea)
1566	{
1567	float len = 1;
1568
1569	if (pvsUseLen)
1570	len = SqrDistance(entP, extP);
1571
1572	// use length of rays to approximate volume
1573	if (Ray::BACK && Ray::COINCIDENT)
1574	pBack += len;
1575	if (Ray::FRONT && Ray::COINCIDENT)
1576	pFront += len;
1577	if (Ray::FRONT_BACK \|\| Ray::BACK_FRONT)
1578	{
1579	if (pvsUseLen)
1580	{
1581	const Vector3 extp = ray->Extrap(maxT);
1582	const float t = candidatePlane.FindT(ray->GetLoc(), extp);
1583
1584	const float newT = t * maxT;
1585	const float newLen = SqrDistance(ray->Extrap(newT), extp);
1586
1587	if (Ray::FRONT_BACK)
1588	{
1589	pFront += len - newLen;
1590	pBack += newLen;
1591	}
1592	else
1593	{
1594	pBack += len - newLen;
1595	pFront += newLen;
1596	}
1597	}
1598	else
1599	{
1600	++ pFront;
1601	++ pBack;
1602	}
1603	}
1604	}
1605	}
1606	}
1607
1608	const float raysSize = (float)rays.size() + Limits::Small;
1609
1610	if (mSplitPlaneStrategy & LEAST_RAY_SPLITS)
1611	val += mLeastRaySplitsFactor * sumRaySplits / raysSize;
1612
1613	if (mSplitPlaneStrategy & BALANCED_RAYS)
1614	val += mBalancedRaysFactor * fabs(sumBalancedRays) / raysSize;
1615
1616	const float denom = pOverall * (float)pvs * 2.0f + Limits::Small;
1617
1618	if (mSplitPlaneStrategy & PVS)
1619	{
1620	val += mPvsFactor * (frontPvs * pFront + (backPvs * pBack)) / denom;
1621
1622	// give penalty to unbalanced split
1623	if (1)
1624	if (((pFront * 0.2 + Limits::Small) > pBack) \|\|
1625	(pFront < (pBack * 0.2 + Limits::Small)))
1626	val += 0.5;
1627	}
1628
1629
1630	#ifdef _DEBUG
1631	Debug << "totalpvs: " << pvs << " ptotal: " << pOverall
1632	<< " frontpvs: " << frontPvs << " pFront: " << pFront
1633	<< " backpvs: " << backPvs << " pBack: " << pBack << endl << endl;
1634	#endif
1635
1636	return val;
1637	}
1638
1639	void BspTree::AddObjToPvs(Intersectable *obj,
1640	const int cf,
1641	int &frontPvs,
1642	int &backPvs) const
1643	{
1644	if (!obj)
1645	return;
1646	// TODO: does this really belong to no pvs?
1647	//if (cf == Ray::COINCIDENT) return;
1648
1649	// object belongs to both PVS
1650	const bool bothSides = (cf == Ray::FRONT_BACK) \|\|
1651	(cf == Ray::BACK_FRONT) \|\|
1652	(cf == Ray::COINCIDENT);
1653
1654	if ((cf == Ray::FRONT) \|\| bothSides)
1655	{
1656	if ((obj->mMailbox != sFrontId) &&
1657	(obj->mMailbox != sFrontAndBackId))
1658	{
1659	++ frontPvs;
1660
1661	if (obj->mMailbox == sBackId)
1662	obj->mMailbox = sFrontAndBackId;
1663	else
1664	obj->mMailbox = sFrontId;
1665	}
1666	}
1667
1668	if ((cf == Ray::BACK) \|\| bothSides)
1669	{
1670	if ((obj->mMailbox != sBackId) &&
1671	(obj->mMailbox != sFrontAndBackId))
1672	{
1673	++ backPvs;
1674
1675	if (obj->mMailbox == sFrontId)
1676	obj->mMailbox = sFrontAndBackId;
1677	else
1678	obj->mMailbox = sBackId;
1679	}
1680	}
1681	}
1682
1683	float BspTree::SplitPlaneCost(const Plane3 &candidatePlane,
1684	BspTraversalData &data) const
1685	{
1686	float val = 0;
1687
1688	if (mSplitPlaneStrategy & VERTICAL_AXIS)
1689	{
1690	Vector3 tinyAxis(0,0,0); tinyAxis[mBox.Size().TinyAxis()] = 1.0f;
1691	// we put a penalty on the dot product between the "tiny" vertical axis
1692	// and the split plane axis
1693	val += mVerticalSplitsFactor *
1694	fabs(DotProd(candidatePlane.mNormal, tinyAxis));
1695	}
1696
1697	// the following criteria loop over all polygons to find the cost value
1698	if ((mSplitPlaneStrategy & BALANCED_POLYS) \|\|
1699	(mSplitPlaneStrategy & LEAST_SPLITS) \|\|
1700	(mSplitPlaneStrategy & LARGEST_POLY_AREA) \|\|
1701	(mSplitPlaneStrategy & BALANCED_VIEW_CELLS) \|\|
1702	(mSplitPlaneStrategy & BLOCKED_RAYS))
1703	{
1704	val += SplitPlaneCost(candidatePlane, *data.mPolygons);
1705	}
1706
1707	// the following criteria loop over all rays to find the cost value
1708	if ((mSplitPlaneStrategy & BALANCED_RAYS) \|\|
1709	(mSplitPlaneStrategy & LEAST_RAY_SPLITS) \|\|
1710	(mSplitPlaneStrategy & PVS))
1711	{
1712	val += SplitPlaneCost(candidatePlane, *data.mRays, data.mPvs,
1713	data.mArea, *data.mGeometry);
1714	}
1715
1716	// return linear combination of the sums
1717	return val;
1718	}
1719
1720	void BspTree::CollectLeaves(vector<BspLeaf *> &leaves) const
1721	{
1722	stack<BspNode *> nodeStack;
1723	nodeStack.push(mRoot);
1724
1725	while (!nodeStack.empty())
1726	{
1727	BspNode *node = nodeStack.top();
1728
1729	nodeStack.pop();
1730
1731	if (node->IsLeaf())
1732	{
1733	BspLeaf leaf = (BspLeaf )node;
1734	leaves.push_back(leaf);
1735	}
1736	else
1737	{
1738	BspInterior interior = dynamic_cast<BspInterior >(node);
1739
1740	nodeStack.push(interior->GetBack());
1741	nodeStack.push(interior->GetFront());
1742	}
1743	}
1744	}
1745
1746	AxisAlignedBox3 BspTree::GetBoundingBox() const
1747	{
1748	return mBox;
1749	}
1750
1751	BspNode *BspTree::GetRoot() const
1752	{
1753	return mRoot;
1754	}
1755
1756	void BspTree::EvaluateLeafStats(const BspTraversalData &data)
1757	{
1758	// the node became a leaf -> evaluate stats for leafs
1759	BspLeaf leaf = dynamic_cast<BspLeaf >(data.mNode);
1760
1761	// store maximal and minimal depth
1762	if (data.mDepth > mStat.maxDepth)
1763	mStat.maxDepth = data.mDepth;
1764
1765	if (data.mDepth < mStat.minDepth)
1766	mStat.minDepth = data.mDepth;
1767
1768	// accumulate depth to compute average depth
1769	mStat.accumDepth += data.mDepth;
1770
1771
1772	if (data.mDepth >= mTermMaxDepth)
1773	++ mStat.maxDepthNodes;
1774
1775	if (data.mPvs < mTermMinPvs)
1776	++ mStat.minPvsNodes;
1777
1778	if ((int)data.mRays->size() < mTermMinRays)
1779	++ mStat.minRaysNodes;
1780
1781	if (data.GetAvgRayContribution() > mTermMaxRayContribution)
1782	++ mStat.maxRayContribNodes;
1783
1784	if (data.mGeometry->GetArea() <= mTermMinArea)
1785	++ mStat.minAreaNodes;
1786
1787	#ifdef _DEBUG
1788	Debug << "BSP stats: "
1789	<< "Depth: " << data.mDepth << " (max: " << mTermMaxDepth << "), "
1790	<< "PVS: " << data.mPvs << " (min: " << mTermMinPvs << "), "
1791	<< "Area: " << data.mArea << " (min: " << mTermMinArea << "), "
1792	<< "#polygons: " << (int)data.mPolygons->size() << " (max: " << mTermMinPolys << "), "
1793	<< "#rays: " << (int)data.mRays->size() << " (max: " << mTermMinRays << "), "
1794	<< "#pvs: " << leaf->GetViewCell()->GetPvs().GetSize() << "=, "
1795	<< "#avg ray contrib (pvs): " << (float)data.mPvs / (float)data.mRays->size() << endl;
1796	#endif
1797	}
1798
1799	int BspTree::CastRay(Ray &ray)
1800	{
1801	int hits = 0;
1802
1803	stack<BspRayTraversalData> tStack;
1804
1805	float maxt, mint;
1806
1807	if (!BoundRay(ray, mint, maxt))
1808	return 0;
1809
1810	Intersectable::NewMail();
1811
1812	Vector3 entp = ray.Extrap(mint);
1813	Vector3 extp = ray.Extrap(maxt);
1814
1815	BspNode *node = mRoot;
1816	BspNode *farChild = NULL;
1817
1818	while (1)
1819	{
1820	if (!node->IsLeaf())
1821	{
1822	BspInterior in = (BspInterior ) node;
1823
1824	Plane3 *splitPlane = in->GetPlane();
1825
1826	int entSide = splitPlane->Side(entp);
1827	int extSide = splitPlane->Side(extp);
1828
1829	Vector3 intersection;
1830
1831	if (entSide < 0)
1832	{
1833	node = in->GetBack();
1834
1835	if(extSide <= 0) // plane does not split ray => no far child
1836	continue;
1837
1838	farChild = in->GetFront(); // plane splits ray
1839
1840	} else if (entSide > 0)
1841	{
1842	node = in->GetFront();
1843
1844	if (extSide >= 0) // plane does not split ray => no far child
1845	continue;
1846
1847	farChild = in->GetBack(); // plane splits ray
1848	}
1849	else // ray and plane are coincident
1850	{
1851	// WHAT TO DO IN THIS CASE ?
1852	//break;
1853	node = in->GetFront();
1854	continue;
1855	}
1856
1857	// push data for far child
1858	tStack.push(BspRayTraversalData(farChild, extp, maxt));
1859
1860	// find intersection of ray segment with plane
1861	float t;
1862	extp = splitPlane->FindIntersection(ray.GetLoc(), extp, &t);
1863	maxt *= t;
1864
1865	} else // reached leaf => intersection with view cell
1866	{
1867	BspLeaf leaf = dynamic_cast<BspLeaf >(node);
1868
1869	if (!leaf->mViewCell->Mailed())
1870	{
1871	ray.bspIntersections.push_back(Ray::BspIntersection(maxt, leaf));
1872	leaf->mViewCell->Mail();
1873	++ hits;
1874	}
1875
1876	//-- fetch the next far child from the stack
1877	if (tStack.empty())
1878	break;
1879
1880	entp = extp;
1881	mint = maxt; // NOTE: need this?
1882
1883	if (ray.GetType() == Ray::LINE_SEGMENT && mint > 1.0f)
1884	break;
1885
1886	BspRayTraversalData &s = tStack.top();
1887
1888	node = s.mNode;
1889	extp = s.mExitPoint;
1890	maxt = s.mMaxT;
1891
1892	tStack.pop();
1893	}
1894	}
1895
1896	return hits;
1897	}
1898
1899	bool BspTree::Export(const string filename)
1900	{
1901	Exporter *exporter = Exporter::GetExporter(filename);
1902
1903	if (exporter)
1904	{
1905	exporter->ExportBspTree(*this);
1906	return true;
1907	}
1908
1909	return false;
1910	}
1911
1912	void BspTree::CollectViewCells(ViewCellContainer &viewCells) const
1913	{
1914	stack<BspNode *> nodeStack;
1915	nodeStack.push(mRoot);
1916
1917	ViewCell::NewMail();
1918
1919	while (!nodeStack.empty())
1920	{
1921	BspNode *node = nodeStack.top();
1922	nodeStack.pop();
1923
1924	if (node->IsLeaf())
1925	{
1926	ViewCell viewCell = dynamic_cast<BspLeaf >(node)->mViewCell;
1927
1928	if (!viewCell->Mailed())
1929	{
1930	viewCell->Mail();
1931	viewCells.push_back(viewCell);
1932	}
1933	}
1934	else
1935	{
1936	BspInterior interior = dynamic_cast<BspInterior >(node);
1937
1938	nodeStack.push(interior->mFront);
1939	nodeStack.push(interior->mBack);
1940	}
1941	}
1942	}
1943
1944	void BspTree::EvaluateViewCellsStats(BspViewCellsStatistics &stat) const
1945	{
1946	stat.Reset();
1947
1948	stack<BspNode *> nodeStack;
1949	nodeStack.push(mRoot);
1950
1951	ViewCell::NewMail();
1952
1953	// exclude root cell
1954	mRootCell->Mail();
1955
1956	while (!nodeStack.empty())
1957	{
1958	BspNode *node = nodeStack.top();
1959	nodeStack.pop();
1960
1961	if (node->IsLeaf())
1962	{
1963	++ stat.bspLeaves;
1964
1965	BspViewCell viewCell = dynamic_cast<BspLeaf >(node)->mViewCell;
1966
1967	if (!viewCell->Mailed())
1968	{
1969	viewCell->Mail();
1970
1971	++ stat.viewCells;
1972	const int pvsSize = viewCell->GetPvs().GetSize();
1973
1974	stat.pvs += pvsSize;
1975
1976	if (pvsSize < 1)
1977	++ stat.emptyPvs;
1978
1979	if (pvsSize > stat.maxPvs)
1980	stat.maxPvs = pvsSize;
1981
1982	if (pvsSize < stat.minPvs)
1983	stat.minPvs = pvsSize;
1984
1985	if ((int)viewCell->mBspLeaves.size() > stat.maxBspLeaves)
1986	stat.maxBspLeaves = (int)viewCell->mBspLeaves.size();
1987	}
1988	}
1989	else
1990	{
1991	BspInterior interior = dynamic_cast<BspInterior >(node);
1992
1993	nodeStack.push(interior->mFront);
1994	nodeStack.push(interior->mBack);
1995	}
1996	}
1997	}
1998
1999	BspTreeStatistics &BspTree::GetStat()
2000	{
2001	return mStat;
2002	}
2003
2004	float BspTree::AccumulatedRayLength(BoundedRayContainer &rays) const
2005	{
2006	float len = 0;
2007
2008	BoundedRayContainer::const_iterator it, it_end = rays.end();
2009
2010	for (it = rays.begin(); it != it_end; ++ it)
2011	{
2012	len += SqrDistance((it)->mRay->Extrap((it)->mMinT),
2013	(it)->mRay->Extrap((it)->mMaxT));
2014	}
2015
2016	return len;
2017	}
2018
2019	int BspTree::SplitRays(const Plane3 &plane,
2020	BoundedRayContainer &rays,
2021	BoundedRayContainer &frontRays,
2022	BoundedRayContainer &backRays)
2023	{
2024	int splits = 0;
2025
2026	while (!rays.empty())
2027	{
2028	BoundedRay *bRay = rays.back();
2029	Ray *ray = bRay->mRay;
2030	float minT = bRay->mMinT;
2031	float maxT = bRay->mMaxT;
2032
2033	rays.pop_back();
2034
2035	Vector3 entP, extP;
2036
2037	const int cf =
2038	ray->ClassifyPlane(plane, minT, maxT, entP, extP);
2039
2040	// set id to ray classification
2041	ray->SetId(cf);
2042
2043	switch (cf)
2044	{
2045	case Ray::COINCIDENT: // TODO: should really discard ray?
2046	frontRays.push_back(bRay);
2047	//DEL_PTR(bRay);
2048	break;
2049	case Ray::BACK:
2050	backRays.push_back(bRay);
2051	break;
2052	case Ray::FRONT:
2053	frontRays.push_back(bRay);
2054	break;
2055	case Ray::FRONT_BACK:
2056	{
2057	// find intersection of ray segment with plane
2058	const float t = plane.FindT(ray->GetLoc(), extP);
2059
2060	const float newT = t * maxT;
2061
2062	frontRays.push_back(new BoundedRay(ray, minT, newT));
2063	backRays.push_back(new BoundedRay(ray, newT, maxT));
2064
2065	DEL_PTR(bRay);
2066	}
2067	break;
2068	case Ray::BACK_FRONT:
2069	{
2070	// find intersection of ray segment with plane
2071	const float t = plane.FindT(ray->GetLoc(), extP);
2072	const float newT = t * bRay->mMaxT;
2073
2074	backRays.push_back(new BoundedRay(ray, bRay->mMinT, newT));
2075	frontRays.push_back(new BoundedRay(ray, newT, bRay->mMaxT));
2076	DEL_PTR(bRay);
2077
2078	++ splits;
2079	}
2080	break;
2081	default:
2082	Debug << "Should not come here 4" << endl;
2083	break;
2084	}
2085	}
2086
2087	return splits;
2088	}
2089
2090	void BspTree::ExtractHalfSpaces(BspNode *n, vector<Plane3> &halfSpaces) const
2091	{
2092	BspNode *lastNode;
2093	do
2094	{
2095	lastNode = n;
2096
2097	// want to get planes defining geometry of this node => don't take
2098	// split plane of node itself
2099	n = n->GetParent();
2100
2101	if (n)
2102	{
2103	BspInterior interior = dynamic_cast<BspInterior >(n);
2104	Plane3 halfSpace = dynamic_cast<BspInterior >(interior)->GetPlane();
2105
2106	if (interior->mFront != lastNode)
2107	halfSpace.ReverseOrientation();
2108
2109	halfSpaces.push_back(halfSpace);
2110	}
2111	}
2112	while (n);
2113	}
2114
2115	void BspTree::ConstructGeometry(BspNode *n, BspNodeGeometry &cell) const
2116	{
2117	PolygonContainer polys;
2118	ConstructGeometry(n, polys);
2119	cell.mPolys = polys;
2120	}
2121
2122	void BspTree::ConstructGeometry(BspViewCell *vc, PolygonContainer &cell) const
2123	{
2124	vector<BspLeaf *> leaves = vc->mBspLeaves;
2125
2126	vector<BspLeaf *>::const_iterator it, it_end = leaves.end();
2127
2128	for (it = leaves.begin(); it != it_end; ++ it)
2129	ConstructGeometry(*it, cell);
2130	}
2131
2132
2133	void BspTree::ConstructGeometry(BspNode *n, PolygonContainer &cell) const
2134	{
2135	vector<Plane3> halfSpaces;
2136	ExtractHalfSpaces(n, halfSpaces);
2137
2138	PolygonContainer candidatePolys;
2139
2140	// bounded planes are added to the polygons (reverse polygons
2141	// as they have to be outfacing
2142	for (int i = 0; i < (int)halfSpaces.size(); ++ i)
2143	{
2144	Polygon3 *p = GetBoundingBox().CrossSection(halfSpaces[i]);
2145
2146	if (p->Valid())
2147	{
2148	candidatePolys.push_back(p->CreateReversePolygon());
2149	DEL_PTR(p);
2150	}
2151	}
2152
2153	// add faces of bounding box (also could be faces of the cell)
2154	for (int i = 0; i < 6; ++ i)
2155	{
2156	VertexContainer vertices;
2157
2158	for (int j = 0; j < 4; ++ j)
2159	vertices.push_back(mBox.GetFace(i).mVertices[j]);
2160
2161	candidatePolys.push_back(new Polygon3(vertices));
2162	}
2163
2164	for (int i = 0; i < (int)candidatePolys.size(); ++ i)
2165	{
2166	// polygon is split by all other planes
2167	for (int j = 0; (j < (int)halfSpaces.size()) && candidatePolys[i]; ++ j)
2168	{
2169	if (i == j) // polygon and plane are coincident
2170	continue;
2171
2172	VertexContainer splitPts;
2173	Polygon3 frontPoly, backPoly;
2174
2175	const int cf = candidatePolys[i]->ClassifyPlane(halfSpaces[j]);
2176
2177	switch (cf)
2178	{
2179	case Polygon3::SPLIT:
2180	frontPoly = new Polygon3();
2181	backPoly = new Polygon3();
2182
2183	candidatePolys[i]->Split(halfSpaces[j],
2184	*frontPoly,
2185	*backPoly);
2186
2187	DEL_PTR(candidatePolys[i]);
2188
2189	if (frontPoly->Valid())
2190	candidatePolys[i] = frontPoly;
2191	else
2192	DEL_PTR(frontPoly);
2193
2194	DEL_PTR(backPoly);
2195	break;
2196	case Polygon3::BACK_SIDE:
2197	DEL_PTR(candidatePolys[i]);
2198	break;
2199	// just take polygon as it is
2200	case Polygon3::FRONT_SIDE:
2201	case Polygon3::COINCIDENT:
2202	default:
2203	break;
2204	}
2205	}
2206
2207	if (candidatePolys[i])
2208	cell.push_back(candidatePolys[i]);
2209	}
2210	}
2211
2212
2213	int BspTree::FindNeighbors(BspNode n, vector<BspLeaf > &neighbors,
2214	const bool onlyUnmailed) const
2215	{
2216	PolygonContainer cell;
2217
2218	ConstructGeometry(n, cell);
2219
2220	stack<BspNode *> nodeStack;
2221	nodeStack.push(mRoot);
2222
2223	// planes needed to verify that we found neighbor leaf.
2224	vector<Plane3> halfSpaces;
2225	ExtractHalfSpaces(n, halfSpaces);
2226
2227	while (!nodeStack.empty())
2228	{
2229	BspNode *node = nodeStack.top();
2230	nodeStack.pop();
2231
2232	if (node->IsLeaf())
2233	{
2234	if (node != n && (!onlyUnmailed \|\| !node->Mailed()))
2235	{
2236	// test all planes of current node if candidate really
2237	// is neighbour
2238	PolygonContainer neighborCandidate;
2239	ConstructGeometry(node, neighborCandidate);
2240
2241	bool isAdjacent = true;
2242	for (int i = 0; (i < halfSpaces.size()) && isAdjacent; ++ i)
2243	{
2244	const int cf =
2245	Polygon3::ClassifyPlane(neighborCandidate, halfSpaces[i]);
2246
2247	if (cf == Polygon3::BACK_SIDE)
2248	isAdjacent = false;
2249	}
2250
2251	if (isAdjacent)
2252	neighbors.push_back(dynamic_cast<BspLeaf *>(node));
2253
2254	CLEAR_CONTAINER(neighborCandidate);
2255	}
2256	}
2257	else
2258	{
2259	BspInterior interior = dynamic_cast<BspInterior >(node);
2260
2261	const int cf = Polygon3::ClassifyPlane(cell, interior->mPlane);
2262
2263	if (cf == Polygon3::FRONT_SIDE)
2264	nodeStack.push(interior->mFront);
2265	else
2266	if (cf == Polygon3::BACK_SIDE)
2267	nodeStack.push(interior->mBack);
2268	else
2269	{
2270	// random decision
2271	nodeStack.push(interior->mBack);
2272	nodeStack.push(interior->mFront);
2273	}
2274	}
2275	}
2276
2277	CLEAR_CONTAINER(cell);
2278	return (int)neighbors.size();
2279	}
2280
2281	BspLeaf *BspTree::GetRandomLeaf(const Plane3 &halfspace)
2282	{
2283	stack<BspNode *> nodeStack;
2284	nodeStack.push(mRoot);
2285
2286	int mask = rand();
2287
2288	while (!nodeStack.empty())
2289	{
2290	BspNode *node = nodeStack.top();
2291	nodeStack.pop();
2292
2293	if (node->IsLeaf())
2294	{
2295	return dynamic_cast<BspLeaf *>(node);
2296	}
2297	else
2298	{
2299	BspInterior interior = dynamic_cast<BspInterior >(node);
2300
2301	BspNode *next;
2302
2303	PolygonContainer cell;
2304
2305	// todo: not very efficient: constructs full cell everytime
2306	ConstructGeometry(interior, cell);
2307
2308	const int cf = Polygon3::ClassifyPlane(cell, halfspace);
2309
2310	if (cf == Polygon3::BACK_SIDE)
2311	next = interior->mFront;
2312	else
2313	if (cf == Polygon3::FRONT_SIDE)
2314	next = interior->mFront;
2315	else
2316	{
2317	// random decision
2318	if (mask & 1)
2319	next = interior->mBack;
2320	else
2321	next = interior->mFront;
2322	mask = mask >> 1;
2323	}
2324
2325	nodeStack.push(next);
2326	}
2327	}
2328
2329	return NULL;
2330	}
2331
2332	BspLeaf *BspTree::GetRandomLeaf(const bool onlyUnmailed)
2333	{
2334	stack<BspNode *> nodeStack;
2335
2336	nodeStack.push(mRoot);
2337
2338	int mask = rand();
2339
2340	while (!nodeStack.empty())
2341	{
2342	BspNode *node = nodeStack.top();
2343	nodeStack.pop();
2344
2345	if (node->IsLeaf())
2346	{
2347	if ( (!onlyUnmailed \|\| !node->Mailed()) )
2348	return dynamic_cast<BspLeaf *>(node);
2349	}
2350	else
2351	{
2352	BspInterior interior = dynamic_cast<BspInterior >(node);
2353
2354	// random decision
2355	if (mask & 1)
2356	nodeStack.push(interior->mBack);
2357	else
2358	nodeStack.push(interior->mFront);
2359
2360	mask = mask >> 1;
2361	}
2362	}
2363
2364	return NULL;
2365	}
2366
2367	int BspTree::ComputePvsSize(const BoundedRayContainer &rays) const
2368	{
2369	int pvsSize = 0;
2370
2371	BoundedRayContainer::const_iterator rit, rit_end = rays.end();
2372
2373	Intersectable::NewMail();
2374
2375	for (rit = rays.begin(); rit != rays.end(); ++ rit)
2376	{
2377	Ray ray = (rit)->mRay;
2378
2379	if (!ray->intersections.empty())
2380	{
2381	if (!ray->intersections[0].mObject->Mailed())
2382	{
2383	ray->intersections[0].mObject->Mail();
2384	++ pvsSize;
2385	}
2386	}
2387	if (ray->sourceObject.mObject)
2388	{
2389	if (!ray->sourceObject.mObject->Mailed())
2390	{
2391	ray->sourceObject.mObject->Mail();
2392	++ pvsSize;
2393	}
2394	}
2395	}
2396
2397	return pvsSize;
2398	}
2399
2400	/*************************************************************
2401	* BspNodeGeometry Implementation *
2402	*************************************************************/
2403
2404	BspNodeGeometry::~BspNodeGeometry()
2405	{
2406	CLEAR_CONTAINER(mPolys);
2407	}
2408
2409	float BspNodeGeometry::GetArea() const
2410	{
2411	return Polygon3::GetArea(mPolys);
2412	}
2413
2414	void BspNodeGeometry::SplitGeometry(BspNodeGeometry &front,
2415	BspNodeGeometry &back,
2416	const BspTree &tree,
2417	const Plane3 &splitPlane) const
2418	{
2419	// get cross section of new polygon
2420	Polygon3 *planePoly = tree.GetBoundingBox().CrossSection(splitPlane);
2421
2422	planePoly = SplitPolygon(planePoly, tree);
2423
2424	//-- plane poly splits all other cell polygons
2425	for (int i = 0; i < (int)mPolys.size(); ++ i)
2426	{
2427	const int cf = mPolys[i]->ClassifyPlane(splitPlane, 0.00001f);
2428
2429	// split new polygon with all previous planes
2430	switch (cf)
2431	{
2432	case Polygon3::SPLIT:
2433	{
2434	Polygon3 *poly = new Polygon3(mPolys[i]->mVertices);
2435
2436	Polygon3 *frontPoly = new Polygon3();
2437	Polygon3 *backPoly = new Polygon3();
2438
2439	poly->Split(splitPlane, frontPoly, backPoly);
2440
2441	DEL_PTR(poly);
2442
2443	if (frontPoly->Valid())
2444	front.mPolys.push_back(frontPoly);
2445	else
2446	DEL_PTR(frontPoly);
2447
2448	if (backPoly->Valid())
2449	back.mPolys.push_back(backPoly);
2450	else
2451	DEL_PTR(backPoly);
2452	}
2453
2454	break;
2455	case Polygon3::BACK_SIDE:
2456	back.mPolys.push_back(new Polygon3(mPolys[i]->mVertices));
2457	break;
2458	case Polygon3::FRONT_SIDE:
2459	front.mPolys.push_back(new Polygon3(mPolys[i]->mVertices));
2460	break;
2461	case Polygon3::COINCIDENT:
2462	//front.mPolys.push_back(CreateReversePolygon(mPolys[i]));
2463	back.mPolys.push_back(new Polygon3(mPolys[i]->mVertices));
2464	break;
2465	default:
2466	break;
2467	}
2468	}
2469
2470	//-- finally add the new polygon to the child cells
2471	if (planePoly)
2472	{
2473	// add polygon with normal pointing into positive half space to back cell
2474	back.mPolys.push_back(planePoly);
2475	// add polygon with reverse orientation to front cell
2476	front.mPolys.push_back(planePoly->CreateReversePolygon());
2477	}
2478
2479	//Debug << "returning new geometry " << mPolys.size() << " f: " << front.mPolys.size() << " b: " << back.mPolys.size() << endl;
2480	//Debug << "old area " << GetArea() << " f: " << front.GetArea() << " b: " << back.GetArea() << endl;
2481	}
2482
2483	Polygon3 BspNodeGeometry::SplitPolygon(Polygon3 planePoly,
2484	const BspTree &tree) const
2485	{
2486	// polygon is split by all other planes
2487	for (int i = 0; (i < (int)mPolys.size()) && planePoly; ++ i)
2488	{
2489	Plane3 plane = mPolys[i]->GetSupportingPlane();
2490
2491	const int cf =
2492	planePoly->ClassifyPlane(plane, 0.00001f);
2493
2494	// split new polygon with all previous planes
2495	switch (cf)
2496	{
2497	case Polygon3::SPLIT:
2498	{
2499	Polygon3 *frontPoly = new Polygon3();
2500	Polygon3 *backPoly = new Polygon3();
2501
2502	planePoly->Split(plane, frontPoly, backPoly);
2503
2504	// don't need anymore
2505	DEL_PTR(planePoly);
2506	DEL_PTR(frontPoly);
2507
2508	// back polygon is belonging to geometry
2509	if (backPoly->Valid())
2510	planePoly = backPoly;
2511	else
2512	DEL_PTR(backPoly);
2513	}
2514	break;
2515	case Polygon3::FRONT_SIDE:
2516	DEL_PTR(planePoly);
2517	break;
2518	// polygon is taken as it is
2519	case Polygon3::BACK_SIDE:
2520	case Polygon3::COINCIDENT:
2521	default:
2522	break;
2523	}
2524	}
2525
2526	return planePoly;
2527	}
2528
2529	void BspViewCellsStatistics::Print(ostream &app) const
2530	{
2531	app << "===== BspViewCells statistics ===============\n";
2532
2533	app << setprecision(4);
2534
2535	//app << "#N_CTIME ( Construction time [s] )\n" << Time() << " \n";
2536
2537	app << "#N_OVERALLPVS ( objects in PVS )\n" << pvs << endl;
2538
2539	app << "#N_PMAXPVS ( largest PVS )\n" << maxPvs << endl;
2540
2541	app << "#N_PMINPVS ( smallest PVS )\n" << minPvs << endl;
2542
2543	app << "#N_PAVGPVS ( average PVS )\n" << AvgPvs() << endl;
2544
2545	app << "#N_PEMPTYPVS ( view cells with PVS smaller 2 )\n" << emptyPvs << endl;
2546
2547	app << "#N_VIEWCELLS ( number of view cells)\n" << viewCells << endl;
2548
2549	app << "#N_AVGBSPLEAVES (average number of BSP leaves per view cell )\n" << AvgBspLeaves() << endl;
2550
2551	app << "#N_MAXBSPLEAVES ( maximal number of BSP leaves per view cell )\n" << maxBspLeaves << endl;
2552
2553	app << "===== END OF BspViewCells statistics ==========\n";
2554	}

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