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source: trunk/VUT/GtpVisibilityPreprocessor/src/ViewCellBsp.cpp @ 437

Revision 437, 63.7 KB checked in by mattausch, 19 years ago (diff)
detected leak in BspTree? added specialised fast view cell bsp tree called VspBspTree?

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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::sConstructionMethod = FROM_INPUT_VIEW_CELLS;
39
40	int BspTree::sFrontId = 0;
41	int BspTree::sBackId = 0;
42	int BspTree::sFrontAndBackId = 0;
43
44	/****************************************************************/
45	/* class BspNode implementation */
46	/****************************************************************/
47
48	BspNode::BspNode():
49	mParent(NULL)
50	{}
51
52	BspNode::BspNode(BspInterior *parent):
53	mParent(parent)
54	{}
55
56
57	bool BspNode::IsRoot() const
58	{
59	return mParent == NULL;
60	}
61
62	BspInterior *BspNode::GetParent()
63	{
64	return mParent;
65	}
66
67	void BspNode::SetParent(BspInterior *parent)
68	{
69	mParent = parent;
70	}
71
72	/****************************************************************/
73	/* class BspInterior implementation */
74	/****************************************************************/
75
76
77	BspInterior::BspInterior(const Plane3 &plane):
78	mPlane(plane), mFront(NULL), mBack(NULL)
79	{}
80
81	BspInterior::~BspInterior()
82	{
83	DEL_PTR(mFront);
84	DEL_PTR(mBack);
85	}
86
87	bool BspInterior::IsLeaf() const
88	{
89	return false;
90	}
91
92	BspNode *BspInterior::GetBack()
93	{
94	return mBack;
95	}
96
97	BspNode *BspInterior::GetFront()
98	{
99	return mFront;
100	}
101
102	Plane3 *BspInterior::GetPlane()
103	{
104	return &mPlane;
105	}
106
107	void BspInterior::ReplaceChildLink(BspNode oldChild, BspNode newChild)
108	{
109	if (mBack == oldChild)
110	mBack = newChild;
111	else
112	mFront = newChild;
113	}
114
115	void BspInterior::SetupChildLinks(BspNode b, BspNode f)
116	{
117	mBack = b;
118	mFront = f;
119	}
120
121	int BspInterior::SplitPolygons(PolygonContainer &polys,
122	PolygonContainer &frontPolys,
123	PolygonContainer &backPolys,
124	PolygonContainer &coincident)
125	{
126	int splits = 0;
127
128	#ifdef _Debug
129	Debug << "splitting polygons of node " << this << " with plane " << mPlane << endl;
130	#endif
131	while (!polys.empty())
132	{
133	Polygon3 *poly = polys.back();
134	polys.pop_back();
135
136	//Debug << "New polygon with plane: " << poly->GetSupportingPlane() << "\n";
137
138	// classify polygon
139	const int cf = poly->ClassifyPlane(mPlane);
140
141	switch (cf)
142	{
143	case Polygon3::COINCIDENT:
144	coincident.push_back(poly);
145	break;
146	case Polygon3::FRONT_SIDE:
147	frontPolys.push_back(poly);
148	break;
149	case Polygon3::BACK_SIDE:
150	backPolys.push_back(poly);
151	break;
152	case Polygon3::SPLIT:
153	{
154	Polygon3 *front_piece = new Polygon3(poly->mParent);
155	Polygon3 *back_piece = new Polygon3(poly->mParent);
156
157	//-- split polygon into front and back part
158	poly->Split(mPlane, front_piece, back_piece);
159
160	++ splits; // increase number of splits
161
162	//-- inherit rays from parent polygon for blocked ray criterium
163	poly->InheritRays(front_piece, back_piece);
164	//Debug << "p: " << poly->mPiercingRays.size() << " f: " << front_piece->mPiercingRays.size() << " b: " << back_piece->mPiercingRays.size() << endl;
165
166	// check if polygons still valid
167	if (front_piece->Valid())
168	frontPolys.push_back(front_piece);
169	else
170	DEL_PTR(front_piece);
171
172	if (back_piece->Valid())
173	backPolys.push_back(back_piece);
174	else
175	DEL_PTR(back_piece);
176
177	#ifdef _DEBUG
178	Debug << "split " << poly << endl << front_piece << endl << *back_piece << endl;
179	#endif
180	DEL_PTR(poly);
181	}
182	break;
183	default:
184	Debug << "SHOULD NEVER COME HERE\n";
185	break;
186	}
187	}
188
189	return splits;
190	}
191
192	/****************************************************************/
193	/* class BspLeaf implementation */
194	/****************************************************************/
195	BspLeaf::BspLeaf(): mViewCell(NULL)
196	{
197	}
198
199	BspLeaf::BspLeaf(BspViewCell *viewCell):
200	mViewCell(viewCell)
201	{
202	}
203
204	BspLeaf::BspLeaf(BspInterior *parent):
205	BspNode(parent), mViewCell(NULL)
206	{}
207
208	BspLeaf::BspLeaf(BspInterior parent, BspViewCell viewCell):
209	BspNode(parent), mViewCell(viewCell)
210	{
211	}
212
213	BspViewCell *BspLeaf::GetViewCell() const
214	{
215	return mViewCell;
216	}
217
218	void BspLeaf::SetViewCell(BspViewCell *viewCell)
219	{
220	mViewCell = viewCell;
221	}
222
223	bool BspLeaf::IsLeaf() const
224	{
225	return true;
226	}
227
228	void BspLeaf::AddToPvs(const BoundedRayContainer &rays,
229	int &sampleContributions,
230	int &contributingSamples,
231	bool storeLeavesWithRays)
232	{
233	sampleContributions = 0;
234	contributingSamples = 0;
235
236	BoundedRayContainer::const_iterator it, it_end = rays.end();
237
238	// add contributions from samples to the PVS
239	for (it = rays.begin(); it != it_end; ++ it)
240	{
241	int contribution = 0;
242	Ray ray = (it)->mRay;
243
244	if (!ray->intersections.empty())
245	contribution += mViewCell->GetPvs().AddSample(ray->intersections[0].mObject);
246
247	if (ray->sourceObject.mObject)
248	contribution += mViewCell->GetPvs().AddSample(ray->sourceObject.mObject);
249
250	if (contribution > 0)
251	{
252	sampleContributions += contribution;
253	++ contributingSamples;
254	}
255
256	if (storeLeavesWithRays)
257	// warning: intersections not ordered
258	ray->bspIntersections.push_back(Ray::BspIntersection((*it)->mMinT, this));
259	}
260	}
261
262
263	/****************************************************************/
264	/* class BspTree implementation */
265	/****************************************************************/
266
267	BspTree::BspTree(BspViewCell *viewCell):
268	mRootCell(viewCell),
269	mRoot(NULL),
270	mStoreLeavesWithRays(false),
271	mPvsUseArea(true),
272	mGenerateViewCells(true)
273	{
274	Randomize(); // initialise random generator for heuristics
275
276	//-- termination criteria for autopartition
277	environment->GetIntValue("BspTree.Termination.maxDepth", mTermMaxDepth);
278	environment->GetIntValue("BspTree.Termination.minPvs", mTermMinPvs);
279	environment->GetIntValue("BspTree.Termination.minPolygons", mTermMinPolys);
280	environment->GetIntValue("BspTree.Termination.minRays", mTermMinRays);
281	environment->GetFloatValue("BspTree.Termination.minArea", mTermMinArea);
282	environment->GetFloatValue("BspTree.Termination.maxRayContribution", mTermMaxRayContribution);
283	environment->GetFloatValue("BspTree.Termination.minAccRayLenght", mTermMinAccRayLength);
284
285	//-- factors for bsp tree split plane heuristics
286	environment->GetFloatValue("BspTree.Factor.verticalSplits", mVerticalSplitsFactor);
287	environment->GetFloatValue("BspTree.Factor.largestPolyArea", mLargestPolyAreaFactor);
288	environment->GetFloatValue("BspTree.Factor.blockedRays", mBlockedRaysFactor);
289	environment->GetFloatValue("BspTree.Factor.leastRaySplits", mLeastRaySplitsFactor);
290	environment->GetFloatValue("BspTree.Factor.balancedRays", mBalancedRaysFactor);
291	environment->GetFloatValue("BspTree.Factor.pvsFactor", mPvsFactor);
292	environment->GetFloatValue("BspTree.Factor.leastSplits" , mLeastSplitsFactor);
293	environment->GetFloatValue("BspTree.Factor.balancedPolys", mBalancedPolysFactor);
294	environment->GetFloatValue("BspTree.Factor.balancedViewCells", mBalancedViewCellsFactor);
295	environment->GetFloatValue("BspTree.Termination.ct_div_ci", mCtDivCi);
296
297	//-- termination criteria for axis aligned split
298	environment->GetFloatValue("BspTree.Termination.AxisAligned.ct_div_ci", mAaCtDivCi);
299	environment->GetFloatValue("BspTree.Termination.AxisAligned.maxCostRatio", mMaxCostRatio);
300	environment->GetIntValue("BspTree.Termination.AxisAligned.minPolys",
301	mTermMinPolysForAxisAligned);
302	environment->GetIntValue("BspTree.Termination.AxisAligned.minRays",
303	mTermMinRaysForAxisAligned);
304	environment->GetIntValue("BspTree.Termination.AxisAligned.minObjects",
305	mTermMinObjectsForAxisAligned);
306	//-- partition criteria
307	environment->GetIntValue("BspTree.maxPolyCandidates", mMaxPolyCandidates);
308	environment->GetIntValue("BspTree.maxRayCandidates", mMaxRayCandidates);
309	environment->GetIntValue("BspTree.splitPlaneStrategy", mSplitPlaneStrategy);
310	environment->GetFloatValue("BspTree.AxisAligned.splitBorder", mSplitBorder);
311
312	environment->GetFloatValue("BspTree.Construction.sideTolerance", Vector3::sDistTolerance);
313	Vector3::sDistToleranceSqrt = Vector3::sDistTolerance * Vector3::sDistTolerance;
314
315	// post processing stuff
316	environment->GetIntValue("ViewCells.PostProcessing.minPvsDif", mMinPvsDif);
317	environment->GetIntValue("ViewCells.PostProcessing.minPvs", mMinPvs);
318	environment->GetIntValue("ViewCells.PostProcessing.maxPvs", mMaxPvs);
319
320	Debug << "BSP max depth: " << mTermMaxDepth << endl;
321	Debug << "BSP min PVS: " << mTermMinPvs << endl;
322	Debug << "BSP min area: " << mTermMinArea << endl;
323	Debug << "BSP max polys: " << mTermMinPolys << endl;
324	Debug << "BSP max rays: " << mTermMinRays << endl;
325	Debug << "BSP max polygon candidates: " << mMaxPolyCandidates << endl;
326	Debug << "BSP max plane candidates: " << mMaxRayCandidates << endl;
327
328	Debug << "Split plane strategy: ";
329	if (mSplitPlaneStrategy & RANDOM_POLYGON)
330	Debug << "random polygon ";
331	if (mSplitPlaneStrategy & AXIS_ALIGNED)
332	Debug << "axis aligned ";
333	if (mSplitPlaneStrategy & LEAST_SPLITS)
334	Debug << "least splits ";
335	if (mSplitPlaneStrategy & BALANCED_POLYS)
336	Debug << "balanced polygons ";
337	if (mSplitPlaneStrategy & BALANCED_VIEW_CELLS)
338	Debug << "balanced view cells ";
339	if (mSplitPlaneStrategy & LARGEST_POLY_AREA)
340	Debug << "largest polygon area ";
341	if (mSplitPlaneStrategy & VERTICAL_AXIS)
342	Debug << "vertical axis ";
343	if (mSplitPlaneStrategy & BLOCKED_RAYS)
344	Debug << "blocked rays ";
345	if (mSplitPlaneStrategy & LEAST_RAY_SPLITS)
346	Debug << "least ray splits ";
347	if (mSplitPlaneStrategy & BALANCED_RAYS)
348	Debug << "balanced rays ";
349	if (mSplitPlaneStrategy & PVS)
350	Debug << "pvs";
351
352	Debug << endl;
353	}
354
355	void BspTree::ParseEnvironment()
356	{
357	//-- parse bsp cell tree construction method
358	char constructionMethodStr[60];
359
360	environment->GetStringValue("BspTree.Construction.input", constructionMethodStr);
361
362	sConstructionMethod = FROM_INPUT_VIEW_CELLS;
363
364	if (strcmp(constructionMethodStr, "fromViewCells") == 0)
365	sConstructionMethod = FROM_INPUT_VIEW_CELLS;
366	else if (strcmp(constructionMethodStr, "fromSceneGeometry") == 0)
367	sConstructionMethod = FROM_SCENE_GEOMETRY;
368	else if (strcmp(constructionMethodStr, "fromSamples") == 0)
369	sConstructionMethod = FROM_SAMPLES;
370	else
371	{
372	cerr << "Wrong construction method " << constructionMethodStr << endl;
373	exit(1);
374	}
375
376	Debug << "Construction method: " << constructionMethodStr << endl;
377	}
378
379	const BspTreeStatistics &BspTree::GetStatistics() const
380	{
381	return mStat;
382	}
383
384	void BspTreeStatistics::Print(ostream &app) const
385	{
386	app << "===== BspTree statistics ===============\n";
387
388	app << setprecision(4);
389
390	app << "#N_CTIME ( Construction time [s] )\n" << Time() << " \n";
391
392	app << "#N_NODES ( Number of nodes )\n" << nodes << "\n";
393
394	app << "#N_INTERIORS ( Number of interior nodes )\n" << Interior() << "\n";
395
396	app << "#N_LEAVES ( Number of leaves )\n" << Leaves() << "\n";
397
398	app << "#N_SPLITS ( Number of splits )\n" << splits << "\n";
399
400	app << "#N_PMAXDEPTHLEAVES ( Percentage of leaves at maximum depth )\n"
401	<< maxDepthNodes * 100 / (double)Leaves() << endl;
402
403	app << "#N_PMAXDEPTHLEAVES ( Percentage of leaves at maximum depth )\n"
404	<< maxDepthNodes * 100 / (double)Leaves() << endl;
405
406	app << "#N_PMINPVSLEAVES ( Percentage of leaves with mininimal PVS )\n"
407	<< minPvsNodes * 100 / (double)Leaves() << endl;
408
409	app << "#N_PMINRAYSLEAVES ( Percentage of leaves with minimal number of rays)\n"
410	<< minRaysNodes * 100 / (double)Leaves() << endl;
411
412	app << "#N_PMINAREALEAVES ( Percentage of leaves with mininum area )\n"
413	<< minAreaNodes * 100 / (double)Leaves() << endl;
414
415	app << "#N_PMAXRAYCONTRIBLEAVES ( Percentage of leaves with maximal ray contribution )\n"
416	<< maxRayContribNodes * 100 / (double)Leaves() << endl;
417
418	app << "#N_PMAXDEPTH ( Maximal reached depth )\n" << maxDepth << endl;
419
420	app << "#N_PMINDEPTH ( Minimal reached depth )\n" << minDepth << endl;
421
422	app << "#AVGDEPTH ( average depth )\n" << AvgDepth() << endl;
423
424	app << "#N_INPUT_POLYGONS (number of input polygons )\n" << polys << endl;
425
426	//app << "#N_PVS: " << pvs << endl;
427
428	app << "#N_ROUTPUT_INPUT_POLYGONS ( ratio polygons after subdivision / input polygons )\n" <<
429	(polys + splits) / (double)polys << endl;
430
431	app << "===== END OF BspTree statistics ==========\n";
432	}
433
434
435	BspTree::~BspTree()
436	{
437	DEL_PTR(mRoot);
438	}
439
440	void BspTree::InsertViewCell(ViewCell *viewCell)
441	{
442	PolygonContainer *polys = new PolygonContainer();
443
444	// don't generate new view cell, insert this one
445	mGenerateViewCells = false;
446	// extract polygons that guide the split process
447	mStat.polys += AddMeshToPolygons(viewCell->GetMesh(), *polys, viewCell);
448	mBox.Include(viewCell->GetBox()); // add to BSP aabb
449
450	InsertPolygons(polys);
451	}
452
453	void BspTree::InsertPolygons(PolygonContainer *polys)
454	{
455	std::stack<BspTraversalData> tStack;
456
457	// traverse existing tree or create new tree
458	if (!mRoot)
459	mRoot = new BspLeaf();
460
461	tStack.push(BspTraversalData(mRoot, polys, 0, mRootCell, new BoundedRayContainer(), 0,
462	mBox.SurfaceArea(), new BspNodeGeometry()));
463
464	while (!tStack.empty())
465	{
466	// filter polygons donw the tree
467	BspTraversalData tData = tStack.top();
468	tStack.pop();
469
470	if (!tData.mNode->IsLeaf())
471	{
472	BspInterior interior = dynamic_cast<BspInterior >(tData.mNode);
473
474	//-- filter view cell polygons down the tree until a leaf is reached
475	if (!tData.mPolygons->empty())
476	{
477	PolygonContainer *frontPolys = new PolygonContainer();
478	PolygonContainer *backPolys = new PolygonContainer();
479	PolygonContainer coincident;
480
481	int splits = 0;
482
483	// split viewcell polygons with respect to split plane
484	splits += interior->SplitPolygons(*tData.mPolygons,
485	*frontPolys,
486	*backPolys,
487	coincident);
488
489	// extract view cells associated with the split polygons
490	ViewCell *frontViewCell = mRootCell;
491	ViewCell *backViewCell = mRootCell;
492
493	BspTraversalData frontData(interior->GetFront(),
494	frontPolys,
495	tData.mDepth + 1,
496	mRootCell,
497	tData.mRays,
498	tData.mPvs,
499	mBox.SurfaceArea(),
500	new BspNodeGeometry());
501
502	BspTraversalData backData(interior->GetBack(),
503	backPolys,
504	tData.mDepth + 1,
505	mRootCell,
506	tData.mRays,
507	tData.mPvs,
508	mBox.SurfaceArea(),
509	new BspNodeGeometry());
510
511	if (!mGenerateViewCells)
512	{
513	ExtractViewCells(frontData,
514	backData,
515	coincident,
516	interior->mPlane);
517	}
518
519	// don't need coincident polygons anymore
520	CLEAR_CONTAINER(coincident);
521
522	mStat.splits += splits;
523
524	// push the children on the stack
525	tStack.push(frontData);
526	tStack.push(backData);
527	}
528
529	// cleanup
530	DEL_PTR(tData.mPolygons);
531	}
532	else
533	{
534	// reached leaf => subdivide current viewcell
535	BspNode *subRoot = Subdivide(tStack, tData);
536	}
537	}
538	}
539
540	int BspTree::AddMeshToPolygons(Mesh mesh, PolygonContainer &polys, MeshInstance parent)
541	{
542	FaceContainer::const_iterator fi;
543
544	// copy the face data to polygons
545	for (fi = mesh->mFaces.begin(); fi != mesh->mFaces.end(); ++ fi)
546	{
547	Polygon3 poly = new Polygon3((fi), mesh);
548
549	if (poly->Valid())
550	{
551	poly->mParent = parent; // set parent intersectable
552	polys.push_back(poly);
553	}
554	else
555	DEL_PTR(poly);
556	}
557	return (int)mesh->mFaces.size();
558	}
559
560	int BspTree::AddToPolygonSoup(const ViewCellContainer &viewCells,
561	PolygonContainer &polys,
562	int maxObjects)
563	{
564	int limit = (maxObjects > 0) ?
565	Min((int)viewCells.size(), maxObjects) : (int)viewCells.size();
566
567	int polysSize = 0;
568
569	for (int i = 0; i < limit; ++ i)
570	{
571	if (viewCells[i]->GetMesh()) // copy the mesh data to polygons
572	{
573	mBox.Include(viewCells[i]->GetBox()); // add to BSP tree aabb
574	polysSize += AddMeshToPolygons(viewCells[i]->GetMesh(), polys, viewCells[i]);
575	}
576	}
577
578	return polysSize;
579	}
580
581	int BspTree::AddToPolygonSoup(const ObjectContainer &objects, PolygonContainer &polys, int maxObjects)
582	{
583	int limit = (maxObjects > 0) ? Min((int)objects.size(), maxObjects) : (int)objects.size();
584
585	for (int i = 0; i < limit; ++i)
586	{
587	Intersectable object = objects[i];//it;
588	Mesh *mesh = NULL;
589
590	switch (object->Type()) // extract the meshes
591	{
592	case Intersectable::MESH_INSTANCE:
593	mesh = dynamic_cast<MeshInstance *>(object)->GetMesh();
594	break;
595	case Intersectable::VIEW_CELL:
596	mesh = dynamic_cast<ViewCell *>(object)->GetMesh();
597	break;
598	// TODO: handle transformed mesh instances
599	default:
600	Debug << "intersectable type not supported" << endl;
601	break;
602	}
603
604	if (mesh) // copy the mesh data to polygons
605	{
606	mBox.Include(object->GetBox()); // add to BSP tree aabb
607	AddMeshToPolygons(mesh, polys, mRootCell);
608	}
609	}
610
611	return (int)polys.size();
612	}
613
614	void BspTree::Construct(const ViewCellContainer &viewCells)
615	{
616	mStat.nodes = 1;
617	mBox.Initialize(); // initialise bsp tree bounding box
618
619	// copy view cell meshes into one big polygon soup
620	PolygonContainer *polys = new PolygonContainer();
621	mStat.polys = AddToPolygonSoup(viewCells, *polys);
622
623	// view cells are given
624	mGenerateViewCells = false;
625	// construct tree from the view cell polygons
626	Construct(polys, new BoundedRayContainer());
627	}
628
629
630	void BspTree::Construct(const ObjectContainer &objects)
631	{
632	mStat.nodes = 1;
633	mBox.Initialize(); // initialise bsp tree bounding box
634
635	PolygonContainer *polys = new PolygonContainer();
636
637	mGenerateViewCells = true;
638	// copy mesh instance polygons into one big polygon soup
639	mStat.polys = AddToPolygonSoup(objects, *polys);
640
641	// construct tree from polygon soup
642	Construct(polys, new BoundedRayContainer());
643	}
644
645	void BspTree::Construct(const RayContainer &sampleRays)
646	{
647	mStat.nodes = 1;
648	mBox.Initialize(); // initialise BSP tree bounding box
649
650	PolygonContainer *polys = new PolygonContainer();
651	BoundedRayContainer *rays = new BoundedRayContainer();
652
653	RayContainer::const_iterator rit, rit_end = sampleRays.end();
654
655	// generate view cells
656	mGenerateViewCells = false;
657
658	long startTime = GetTime();
659
660	Debug << "** Extracting polygons from rays **\n";
661
662	std::map<Face , Polygon3 > facePolyMap;
663
664	//-- extract polygons intersected by the rays
665	for (rit = sampleRays.begin(); rit != rit_end; ++ rit)
666	{
667	Ray ray = rit;
668
669	// get ray-face intersection. Store polygon representing the rays together
670	// with rays intersecting the face.
671	if (!ray->intersections.empty())
672	{
673	MeshInstance obj = dynamic_cast<MeshInstance >(ray->intersections[0].mObject);
674	Face *face = obj->GetMesh()->mFaces[ray->intersections[0].mFace];
675
676	std::map<Face , Polygon3 >::iterator it = facePolyMap.find(face);
677
678	if (it != facePolyMap.end())
679	{
680	//store rays if needed for heuristics
681	if (mSplitPlaneStrategy & BLOCKED_RAYS)
682	(*it).second->mPiercingRays.push_back(ray);
683	}
684	else
685	{ //store rays if needed for heuristics
686	Polygon3 *poly = new Polygon3(face, obj->GetMesh());
687	poly->mParent = obj;
688	polys->push_back(poly);
689
690	if (mSplitPlaneStrategy & BLOCKED_RAYS)
691	poly->mPiercingRays.push_back(ray);
692
693	facePolyMap[face] = poly;
694	}
695	}
696	}
697
698	facePolyMap.clear();
699
700	// compute bounding box
701	Polygon3::IncludeInBox(*polys, mBox);
702
703	//-- store rays
704	for (rit = sampleRays.begin(); rit != rit_end; ++ rit)
705	{
706	Ray ray = rit;
707	ray->SetId(-1); // reset id
708
709	float minT, maxT;
710	if (BoundRay(*ray, minT, maxT))
711	rays->push_back(new BoundedRay(ray, minT, maxT));
712	}
713
714	mStat.polys = (int)polys->size();
715
716	Debug << "** Finished polygon extraction **" << endl;
717	Debug << (int)polys->size() << " polys extracted from " << (int)sampleRays.size() << " rays" << endl;
718	Debug << "extraction time: " << TimeDiff(startTime, GetTime())*1e-3 << "s" << endl;
719
720	Construct(polys, rays);
721	}
722
723	void BspTree::Construct(const ObjectContainer &objects, const RayContainer &sampleRays)
724	{
725	mStat.nodes = 1;
726	mBox.Initialize(); // initialise BSP tree bounding box
727
728	BoundedRayContainer *rays = new BoundedRayContainer();
729	PolygonContainer *polys = new PolygonContainer();
730
731	mGenerateViewCells = true;
732
733	// copy mesh instance polygons into one big polygon soup
734	mStat.polys = AddToPolygonSoup(objects, *polys);
735
736	RayContainer::const_iterator rit, rit_end = sampleRays.end();
737
738	//-- store rays
739	for (rit = sampleRays.begin(); rit != rit_end; ++ rit)
740	{
741	Ray ray = rit;
742	ray->SetId(-1); // reset id
743
744	float minT, maxT;
745	if (BoundRay(*ray, minT, maxT))
746	rays->push_back(new BoundedRay(ray, minT, maxT));
747	}
748
749	Debug << "tree has " << (int)polys->size() << " polys, " << (int)sampleRays.size() << " rays" << endl;
750	Construct(polys, rays);
751	}
752
753	void BspTree::Construct(PolygonContainer polys, BoundedRayContainer rays)
754	{
755	std::stack<BspTraversalData> tStack;
756
757	mRoot = new BspLeaf();
758
759	BspNodeGeometry *cell = new BspNodeGeometry();
760	ConstructGeometry(mRoot, *cell);
761
762	BspTraversalData tData(mRoot, polys, 0, mRootCell, rays,
763	ComputePvsSize(*rays), cell->GetArea(), cell);
764
765	tStack.push(tData);
766
767	mStat.Start();
768	cout << "Contructing bsp tree ... ";
769	long startTime = GetTime();
770	while (!tStack.empty())
771	{
772	tData = tStack.top();
773
774	tStack.pop();
775
776	// subdivide leaf node
777	BspNode *r = Subdivide(tStack, tData);
778
779	if (r == mRoot)
780	Debug << "BSP tree construction time spent at root: " << TimeDiff(startTime, GetTime())*1e-3 << "s" << endl;
781	}
782
783	cout << "finished\n";
784
785	mStat.Stop();
786	}
787
788	bool BspTree::TerminationCriteriaMet(const BspTraversalData &data) const
789	{
790	return
791	(((int)data.mPolygons->size() <= mTermMinPolys) \|\|
792	((int)data.mRays->size() <= mTermMinRays) \|\|
793	(data.mPvs <= mTermMinPvs) \|\|
794	(data.mArea <= mTermMinArea) \|\|
795	(data.mDepth >= mTermMaxDepth) \|\|
796	(data.GetAvgRayContribution() < mTermMaxRayContribution));
797	}
798
799	BspNode *BspTree::Subdivide(BspTraversalStack &tStack, BspTraversalData &tData)
800	{
801	//-- terminate traversal
802	if (TerminationCriteriaMet(tData))
803	{
804	BspLeaf leaf = dynamic_cast<BspLeaf >(tData.mNode);
805
806	BspViewCell *viewCell;
807
808	// generate new view cell for each leaf
809	if (mGenerateViewCells)
810	{
811	viewCell = dynamic_cast<BspViewCell *>(ViewCell::Generate());
812	}
813	else
814	{
815	// add view cell to leaf
816	viewCell = dynamic_cast<BspViewCell *>(tData.mViewCell);
817	}
818
819	leaf->SetViewCell(viewCell);
820	viewCell->mBspLeaves.push_back(leaf);
821
822	//-- add pvs
823	if (viewCell != mRootCell)
824	{
825	int conSamp = 0, sampCon = 0;
826	leaf->AddToPvs(*tData.mRays, conSamp, sampCon);
827
828	mStat.contributingSamples += conSamp;
829	mStat.sampleContributions += sampCon;
830	}
831
832	EvaluateLeafStats(tData);
833
834	//-- clean up
835
836	// discard polygons
837	CLEAR_CONTAINER(*tData.mPolygons);
838	// discard rays
839	CLEAR_CONTAINER(*tData.mRays);
840
841	DEL_PTR(tData.mPolygons);
842	DEL_PTR(tData.mRays);
843	DEL_PTR(tData.mGeometry);
844
845	return leaf;
846	}
847
848	//-- continue subdivision
849	PolygonContainer coincident;
850
851	BspTraversalData tFrontData(NULL, new PolygonContainer(), tData.mDepth + 1, mRootCell,
852	new BoundedRayContainer(), 0, 0, new BspNodeGeometry());
853	BspTraversalData tBackData(NULL, new PolygonContainer(), tData.mDepth + 1, mRootCell,
854	new BoundedRayContainer(), 0, 0, new BspNodeGeometry());
855
856	// create new interior node and two leaf nodes
857	BspInterior *interior =
858	SubdivideNode(tData, tFrontData, tBackData, coincident);
859
860	#ifdef _DEBUG
861	if (frontPolys->empty() && backPolys->empty() && (coincident.size() > 2))
862	{ for (PolygonContainer::iterator it = coincident.begin(); it != coincident.end(); ++it)
863	Debug << (it) << " " << (it)->GetArea() << " " << (*it)->mParent << endl ;
864	Debug << endl;}
865	#endif
866
867	// extract view cells from coincident polygons according to plane normal
868	// only if front or back polygons are empty
869	if (!mGenerateViewCells)
870	{
871	ExtractViewCells(tFrontData,
872	tBackData,
873	coincident,
874	interior->mPlane);
875	}
876
877	// don't need coincident polygons anymory
878	CLEAR_CONTAINER(coincident);
879
880	// push the children on the stack
881	tStack.push(tFrontData);
882	tStack.push(tBackData);
883
884	// cleanup
885	DEL_PTR(tData.mNode);
886	DEL_PTR(tData.mPolygons);
887	DEL_PTR(tData.mRays);
888	DEL_PTR(tData.mGeometry);
889
890	return interior;
891	}
892
893	void BspTree::ExtractViewCells(BspTraversalData &frontData,
894	BspTraversalData &backData,
895	const PolygonContainer &coincident,
896	const Plane3 &splitPlane) const
897	{
898	// if not empty, tree is further subdivided => don't have to find view cell
899	bool foundFront = !frontData.mPolygons->empty();
900	bool foundBack = !frontData.mPolygons->empty();
901
902	PolygonContainer::const_iterator it =
903	coincident.begin(), it_end = coincident.end();
904
905	//-- find first view cells in front and back leafs
906	for (; !(foundFront && foundBack) && (it != it_end); ++ it)
907	{
908	if (DotProd((*it)->GetNormal(), splitPlane.mNormal) > 0)
909	{
910	backData.mViewCell = dynamic_cast<ViewCell >((it)->mParent);
911	foundBack = true;
912	}
913	else
914	{
915	frontData.mViewCell = dynamic_cast<ViewCell >((it)->mParent);
916	foundFront = true;
917	}
918	}
919	}
920
921	BspInterior *BspTree::SubdivideNode(BspTraversalData &tData,
922	BspTraversalData &frontData,
923	BspTraversalData &backData,
924	PolygonContainer &coincident)
925	{
926	mStat.nodes += 2;
927
928	BspLeaf leaf = dynamic_cast<BspLeaf >(tData.mNode);
929	// select subdivision plane
930	BspInterior *interior =
931	new BspInterior(SelectPlane(leaf, tData));
932
933	#ifdef _DEBUG
934	Debug << interior << endl;
935	#endif
936
937	// subdivide rays into front and back rays
938	SplitRays(interior->mPlane, tData.mRays, frontData.mRays, *backData.mRays);
939
940	// subdivide polygons with plane
941	mStat.splits += interior->SplitPolygons(*tData.mPolygons,
942	*frontData.mPolygons,
943	*backData.mPolygons,
944	coincident);
945
946	// compute pvs
947	frontData.mPvs = ComputePvsSize(*frontData.mRays);
948	backData.mPvs = ComputePvsSize(*backData.mRays);
949
950	// split geometry and compute area
951	if (1)
952	{
953	tData.mGeometry->SplitGeometry(*frontData.mGeometry,
954	*backData.mGeometry,
955	*this,
956	interior->mPlane);
957
958
959	frontData.mArea = frontData.mGeometry->GetArea();
960	backData.mArea = backData.mGeometry->GetArea();
961	}
962
963	// compute accumulated ray length
964	//frontData.mAccRayLength = AccumulatedRayLength(*frontData.mRays);
965	//backData.mAccRayLength = AccumulatedRayLength(*backData.mRays);
966
967	//-- create front and back leaf
968
969	BspInterior *parent = leaf->GetParent();
970
971	// replace a link from node's parent
972	if (!leaf->IsRoot())
973	{
974	parent->ReplaceChildLink(leaf, interior);
975	interior->SetParent(parent);
976	}
977	else // new root
978	{
979	mRoot = interior;
980	}
981
982	// and setup child links
983	interior->SetupChildLinks(new BspLeaf(interior), new BspLeaf(interior));
984
985	frontData.mNode = interior->mFront;
986	backData.mNode = interior->mBack;
987
988	//DEL_PTR(leaf);
989	return interior;
990	}
991
992	void BspTree::SortSplitCandidates(const PolygonContainer &polys,
993	const int axis,
994	vector<SortableEntry> &splitCandidates) const
995	{
996	splitCandidates.clear();
997
998	int requestedSize = 2 * (int)polys.size();
999	// creates a sorted split candidates array
1000	splitCandidates.reserve(requestedSize);
1001
1002	PolygonContainer::const_iterator it, it_end = polys.end();
1003
1004	AxisAlignedBox3 box;
1005
1006	// insert all queries
1007	for(it = polys.begin(); it != it_end; ++ it)
1008	{
1009	box.Initialize();
1010	box.Include((it));
1011
1012	splitCandidates.push_back(SortableEntry(SortableEntry::POLY_MIN, box.Min(axis), *it));
1013	splitCandidates.push_back(SortableEntry(SortableEntry::POLY_MAX, box.Max(axis), *it));
1014	}
1015
1016	stable_sort(splitCandidates.begin(), splitCandidates.end());
1017	}
1018
1019
1020	float BspTree::BestCostRatio(const PolygonContainer &polys,
1021	const AxisAlignedBox3 &box,
1022	const int axis,
1023	float &position,
1024	int &objectsBack,
1025	int &objectsFront) const
1026	{
1027	vector<SortableEntry> splitCandidates;
1028
1029	SortSplitCandidates(polys, axis, splitCandidates);
1030
1031	// go through the lists, count the number of objects left and right
1032	// and evaluate the following cost funcion:
1033	// C = ct_div_ci + (ol + or)/queries
1034
1035	int objectsLeft = 0, objectsRight = (int)polys.size();
1036
1037	float minBox = box.Min(axis);
1038	float maxBox = box.Max(axis);
1039	float boxArea = box.SurfaceArea();
1040
1041	float minBand = minBox + mSplitBorder * (maxBox - minBox);
1042	float maxBand = minBox + (1.0f - mSplitBorder) * (maxBox - minBox);
1043
1044	float minSum = 1e20f;
1045	vector<SortableEntry>::const_iterator ci, ci_end = splitCandidates.end();
1046
1047	for(ci = splitCandidates.begin(); ci != ci_end; ++ ci)
1048	{
1049	switch ((*ci).type)
1050	{
1051	case SortableEntry::POLY_MIN:
1052	++ objectsLeft;
1053	break;
1054	case SortableEntry::POLY_MAX:
1055	-- objectsRight;
1056	break;
1057	default:
1058	break;
1059	}
1060
1061	if ((ci).value > minBand && (ci).value < maxBand)
1062	{
1063	AxisAlignedBox3 lbox = box;
1064	AxisAlignedBox3 rbox = box;
1065	lbox.SetMax(axis, (*ci).value);
1066	rbox.SetMin(axis, (*ci).value);
1067
1068	float sum = objectsLeft * lbox.SurfaceArea() +
1069	objectsRight * rbox.SurfaceArea();
1070
1071	if (sum < minSum)
1072	{
1073	minSum = sum;
1074	position = (*ci).value;
1075
1076	objectsBack = objectsLeft;
1077	objectsFront = objectsRight;
1078	}
1079	}
1080	}
1081
1082	float oldCost = (float)polys.size();
1083	float newCost = mAaCtDivCi + minSum / boxArea;
1084	float ratio = newCost / oldCost;
1085
1086
1087	#if 0
1088	Debug << "====================" << endl;
1089	Debug << "costRatio=" << ratio << " pos=" << position<<" t=" << (position - minBox)/(maxBox - minBox)
1090	<< "\t o=(" << objectsBack << "," << objectsFront << ")" << endl;
1091	#endif
1092	return ratio;
1093	}
1094
1095	bool BspTree::SelectAxisAlignedPlane(Plane3 &plane,
1096	const PolygonContainer &polys) const
1097	{
1098	AxisAlignedBox3 box;
1099	box.Initialize();
1100
1101	// create bounding box of region
1102	Polygon3::IncludeInBox(polys, box);
1103
1104	int objectsBack = 0, objectsFront = 0;
1105	int axis = 0;
1106	float costRatio = MAX_FLOAT;
1107	Vector3 position;
1108
1109	//-- area subdivision
1110	for (int i = 0; i < 3; ++ i)
1111	{
1112	float p = 0;
1113	float r = BestCostRatio(polys, box, i, p, objectsBack, objectsFront);
1114
1115	if (r < costRatio)
1116	{
1117	costRatio = r;
1118	axis = i;
1119	position = p;
1120	}
1121	}
1122
1123	if (costRatio >= mMaxCostRatio)
1124	return false;
1125
1126	Vector3 norm(0,0,0); norm[axis] = 1.0f;
1127	plane = Plane3(norm, position);
1128
1129	return true;
1130	}
1131
1132	Plane3 BspTree::SelectPlane(BspLeaf *leaf, BspTraversalData &data)
1133	{
1134	if (data.mPolygons->empty() && data.mRays->empty())
1135	{
1136	Debug << "Warning: No autopartition polygon candidate available\n";
1137
1138	// return axis aligned split
1139	AxisAlignedBox3 box;
1140	box.Initialize();
1141
1142	// create bounding box of region
1143	Polygon3::IncludeInBox(*data.mPolygons, box);
1144
1145	const int axis = box.Size().DrivingAxis();
1146	const Vector3 position = (box.Min()[axis] + box.Max()[axis])*0.5f;
1147
1148	Vector3 norm(0,0,0); norm[axis] = 1.0f;
1149	return Plane3(norm, position);
1150	}
1151
1152	if ((mSplitPlaneStrategy & AXIS_ALIGNED) &&
1153	((int)data.mPolygons->size() > mTermMinPolysForAxisAligned) &&
1154	((int)data.mRays->size() > mTermMinRaysForAxisAligned) &&
1155	((mTermMinObjectsForAxisAligned < 0) \|\|
1156	(Polygon3::ParentObjectsSize(*data.mPolygons) > mTermMinObjectsForAxisAligned)))
1157	{
1158	Plane3 plane;
1159	if (SelectAxisAlignedPlane(plane, *data.mPolygons))
1160	return plane;
1161	}
1162
1163	// simplest strategy: just take next polygon
1164	if (mSplitPlaneStrategy & RANDOM_POLYGON)
1165	{
1166	if (!data.mPolygons->empty())
1167	{
1168	Polygon3 nextPoly = (data.mPolygons)[Random((int)data.mPolygons->size())];
1169	return nextPoly->GetSupportingPlane();
1170	}
1171	else
1172	{
1173	const int candidateIdx = Random((int)data.mRays->size());
1174	BoundedRay bRay = (data.mRays)[candidateIdx];
1175
1176	Ray *ray = bRay->mRay;
1177
1178	const Vector3 minPt = ray->Extrap(bRay->mMinT);
1179	const Vector3 maxPt = ray->Extrap(bRay->mMaxT);
1180
1181	const Vector3 pt = (maxPt + minPt) * 0.5;
1182
1183	const Vector3 normal = ray->GetDir();
1184
1185	return Plane3(normal, pt);
1186	}
1187
1188	return Plane3();
1189	}
1190
1191	// use heuristics to find appropriate plane
1192	return SelectPlaneHeuristics(leaf, data);
1193	}
1194
1195	Plane3 BspTree::SelectPlaneHeuristics(BspLeaf *leaf, BspTraversalData &data)
1196	{
1197	float lowestCost = MAX_FLOAT;
1198	Plane3 bestPlane;
1199	Plane3 plane;
1200
1201	int limit = Min((int)data.mPolygons->size(), mMaxPolyCandidates);
1202
1203	int candidateIdx = limit;
1204
1205	for (int i = 0; i < limit; ++ i)
1206	{
1207	candidateIdx = GetNextCandidateIdx(candidateIdx, *data.mPolygons);
1208
1209	Polygon3 poly = (data.mPolygons)[candidateIdx];
1210	// evaluate current candidate
1211	const float candidateCost =
1212	SplitPlaneCost(poly->GetSupportingPlane(), data);
1213
1214	if (candidateCost < lowestCost)
1215	{
1216	bestPlane = poly->GetSupportingPlane();
1217	lowestCost = candidateCost;
1218	}
1219	}
1220
1221	//Debug << "lowest: " << lowestCost << endl;
1222
1223	//-- choose candidate planes extracted from rays
1224	// we currently use two methods
1225	// 1) take 3 ray endpoints, where two are minimum and one a maximum
1226	// point or the other way round
1227	// 2) take plane normal as plane normal and the midpoint of the ray.
1228	// PROBLEM: does not resemble any point where visibility is likely to change
1229	const BoundedRayContainer *rays = data.mRays;
1230
1231	for (int i = 0; i < mMaxRayCandidates / 2; ++ i)
1232	{
1233	candidateIdx = Random((int)rays->size());
1234	BoundedRay bRay = (rays)[candidateIdx];
1235
1236	Ray *ray = bRay->mRay;
1237
1238	const Vector3 minPt = ray->Extrap(bRay->mMinT);
1239	const Vector3 maxPt = ray->Extrap(bRay->mMaxT);
1240
1241	const Vector3 pt = (maxPt + minPt) * 0.5;
1242
1243	const Vector3 normal = ray->GetDir();
1244
1245	plane = Plane3(normal, pt);
1246
1247	const float candidateCost = SplitPlaneCost(plane, data);
1248
1249	if (candidateCost < lowestCost)
1250	{
1251	bestPlane = plane;
1252
1253	lowestCost = candidateCost;
1254	}
1255	}
1256
1257	//Debug << "lowest: " << lowestCost << endl;
1258	for (int i = 0; i < mMaxRayCandidates / 2; ++ i)
1259	{
1260	Vector3 pt[3];
1261	int idx[3];
1262	int cmaxT = 0;
1263	int cminT = 0;
1264	bool chooseMin = false;
1265
1266	for (int j = 0; j < 3; j ++)
1267	{
1268	idx[j] = Random((int)rays->size() * 2);
1269
1270	if (idx[j] >= (int)rays->size())
1271	{
1272	idx[j] -= (int)rays->size();
1273
1274	chooseMin = (cminT < 2);
1275	}
1276	else
1277	chooseMin = (cmaxT < 2);
1278
1279	BoundedRay bRay = (rays)[idx[j]];
1280	pt[j] = chooseMin ? bRay->mRay->Extrap(bRay->mMinT) : bRay->mRay->Extrap(bRay->mMaxT);
1281	}
1282
1283	plane = Plane3(pt[0], pt[1], pt[2]);
1284
1285	const float candidateCost = SplitPlaneCost(plane, data);
1286
1287	if (candidateCost < lowestCost)
1288	{
1289	//Debug << "choose ray plane 2: " << candidateCost << endl;
1290	bestPlane = plane;
1291
1292	lowestCost = candidateCost;
1293	}
1294	}
1295
1296	#ifdef _DEBUG
1297	Debug << "plane lowest cost: " << lowestCost << endl;
1298	#endif
1299	return bestPlane;
1300	}
1301
1302	int BspTree::GetNextCandidateIdx(int currentIdx, PolygonContainer &polys)
1303	{
1304	const int candidateIdx = Random(currentIdx --);
1305
1306	// swap candidates to avoid testing same plane 2 times
1307	std::swap(polys[currentIdx], polys[candidateIdx]);
1308
1309	return currentIdx;
1310	//return Random((int)polys.size());
1311	}
1312
1313	float BspTree::SplitPlaneCost(const Plane3 &candidatePlane,
1314	const PolygonContainer &polys) const
1315	{
1316	float val = 0;
1317
1318	float sumBalancedPolys = 0;
1319	float sumSplits = 0;
1320	float sumPolyArea = 0;
1321	float sumBalancedViewCells = 0;
1322	float sumBlockedRays = 0;
1323	float totalBlockedRays = 0;
1324	//float totalArea = 0;
1325	int totalViewCells = 0;
1326
1327	// need three unique ids for each type of view cell
1328	// for balanced view cells criterium
1329	ViewCell::NewMail();
1330	const int backId = ViewCell::sMailId;
1331	ViewCell::NewMail();
1332	const int frontId = ViewCell::sMailId;
1333	ViewCell::NewMail();
1334	const int frontAndBackId = ViewCell::sMailId;
1335
1336	PolygonContainer::const_iterator it, it_end = polys.end();
1337
1338	for (it = polys.begin(); it != it_end; ++ it)
1339	{
1340	const int classification = (*it)->ClassifyPlane(candidatePlane);
1341
1342	if (mSplitPlaneStrategy & BALANCED_POLYS)
1343	sumBalancedPolys += sBalancedPolysTable[classification];
1344
1345	if (mSplitPlaneStrategy & LEAST_SPLITS)
1346	sumSplits += sLeastPolySplitsTable[classification];
1347
1348	if (mSplitPlaneStrategy & LARGEST_POLY_AREA)
1349	{
1350	if (classification == Polygon3::COINCIDENT)
1351	sumPolyArea += (*it)->GetArea();
1352	//totalArea += area;
1353	}
1354
1355	if (mSplitPlaneStrategy & BLOCKED_RAYS)
1356	{
1357	const float blockedRays = (float)(*it)->mPiercingRays.size();
1358
1359	if (classification == Polygon3::COINCIDENT)
1360	sumBlockedRays += blockedRays;
1361
1362	totalBlockedRays += blockedRays;
1363	}
1364
1365	// assign view cells to back or front according to classificaion
1366	if (mSplitPlaneStrategy & BALANCED_VIEW_CELLS)
1367	{
1368	MeshInstance viewCell = (it)->mParent;
1369
1370	// assure that we only count a view cell
1371	// once for the front and once for the back side of the plane
1372	if (classification == Polygon3::FRONT_SIDE)
1373	{
1374	if ((viewCell->mMailbox != frontId) &&
1375	(viewCell->mMailbox != frontAndBackId))
1376	{
1377	sumBalancedViewCells += 1.0;
1378
1379	if (viewCell->mMailbox != backId)
1380	viewCell->mMailbox = frontId;
1381	else
1382	viewCell->mMailbox = frontAndBackId;
1383
1384	++ totalViewCells;
1385	}
1386	}
1387	else if (classification == Polygon3::BACK_SIDE)
1388	{
1389	if ((viewCell->mMailbox != backId) &&
1390	(viewCell->mMailbox != frontAndBackId))
1391	{
1392	sumBalancedViewCells -= 1.0;
1393
1394	if (viewCell->mMailbox != frontId)
1395	viewCell->mMailbox = backId;
1396	else
1397	viewCell->mMailbox = frontAndBackId;
1398
1399	++ totalViewCells;
1400	}
1401	}
1402	}
1403	}
1404
1405	const float polysSize = (float)polys.size() + Limits::Small;
1406
1407	// all values should be approx. between 0 and 1 so they can be combined
1408	// and scaled with the factors according to their importance
1409	if (mSplitPlaneStrategy & BALANCED_POLYS)
1410	val += mBalancedPolysFactor * fabs(sumBalancedPolys) / polysSize;
1411
1412	if (mSplitPlaneStrategy & LEAST_SPLITS)
1413	val += mLeastSplitsFactor * sumSplits / polysSize;
1414
1415	if (mSplitPlaneStrategy & LARGEST_POLY_AREA)
1416	// HACK: polys.size should be total area so scaling is between 0 and 1
1417	val += mLargestPolyAreaFactor * (float)polys.size() / sumPolyArea;
1418
1419	if (mSplitPlaneStrategy & BLOCKED_RAYS)
1420	if (totalBlockedRays != 0)
1421	val += mBlockedRaysFactor * (totalBlockedRays - sumBlockedRays) / totalBlockedRays;
1422
1423	if (mSplitPlaneStrategy & BALANCED_VIEW_CELLS)
1424	val += mBalancedViewCellsFactor * fabs(sumBalancedViewCells) /
1425	((float)totalViewCells + Limits::Small);
1426
1427	return val;
1428	}
1429
1430	bool BspTree::BoundRay(const Ray &ray, float &minT, float &maxT) const
1431	{
1432	maxT = 1e6;
1433	minT = 0;
1434
1435	// test with tree bounding box
1436	if (!mBox.GetMinMaxT(ray, &minT, &maxT))
1437	return false;
1438
1439	if (minT < 0) // start ray from origin
1440	minT = 0;
1441
1442	// bound ray or line segment
1443	if ((ray.GetType() == Ray::LOCAL_RAY) &&
1444	!ray.intersections.empty() &&
1445	(ray.intersections[0].mT <= maxT))
1446	{
1447	maxT = ray.intersections[0].mT;
1448	}
1449
1450	return true;
1451	}
1452
1453	inline void BspTree::GenerateUniqueIdsForPvs()
1454	{
1455	Intersectable::NewMail(); sBackId = ViewCell::sMailId;
1456	Intersectable::NewMail(); sFrontId = ViewCell::sMailId;
1457	Intersectable::NewMail(); sFrontAndBackId = ViewCell::sMailId;
1458	}
1459
1460	float BspTree::SplitPlaneCost(const Plane3 &candidatePlane,
1461	const BoundedRayContainer &rays,
1462	const int pvs,
1463	const float area,
1464	const BspNodeGeometry &cell) const
1465	{
1466	float val = 0;
1467
1468	float sumBalancedRays = 0;
1469	float sumRaySplits = 0;
1470
1471	int backId = 0;
1472	int frontId = 0;
1473	int frontAndBackId = 0;
1474
1475	int frontPvs = 0;
1476	int backPvs = 0;
1477
1478	// probability that view point lies in child
1479	float pOverall = 0;
1480	float pFront = 0;
1481	float pBack = 0;
1482
1483	if (mSplitPlaneStrategy & PVS)
1484	{
1485	// create unique ids for pvs heuristics
1486	GenerateUniqueIdsForPvs();
1487
1488	if (mPvsUseArea) // use front and back cell areas to approximate volume
1489	{
1490	// construct child geometry with regard to the candidate split plane
1491	BspNodeGeometry frontCell;
1492	BspNodeGeometry backCell;
1493
1494	cell.SplitGeometry(frontCell, backCell, *this, candidatePlane);
1495
1496	pFront = frontCell.GetArea();
1497	pBack = backCell.GetArea();
1498
1499	pOverall = area;
1500	}
1501	}
1502
1503	BoundedRayContainer::const_iterator rit, rit_end = rays.end();
1504
1505	for (rit = rays.begin(); rit != rays.end(); ++ rit)
1506	{
1507	Ray ray = (rit)->mRay;
1508	const float minT = (*rit)->mMinT;
1509	const float maxT = (*rit)->mMaxT;
1510
1511	Vector3 entP, extP;
1512
1513	const int cf =
1514	ray->ClassifyPlane(candidatePlane, minT, maxT, entP, extP);
1515
1516	if (mSplitPlaneStrategy & LEAST_RAY_SPLITS)
1517	{
1518	sumBalancedRays += sBalancedRaysTable[cf];
1519	}
1520
1521	if (mSplitPlaneStrategy & BALANCED_RAYS)
1522	{
1523	sumRaySplits += sLeastRaySplitsTable[cf];
1524	}
1525
1526	if (mSplitPlaneStrategy & PVS)
1527	{
1528	// in case the ray intersects an object
1529	// assure that we only count the object
1530	// once for the front and once for the back side of the plane
1531
1532	// add the termination object
1533	if (!ray->intersections.empty())
1534	AddObjToPvs(ray->intersections[0].mObject, cf, frontPvs, backPvs);
1535
1536	// add the source object
1537	AddObjToPvs(ray->sourceObject.mObject, cf, frontPvs, backPvs);
1538
1539	if (!mPvsUseArea) // use front and back cell areas to approximate volume
1540	{
1541	float len = Distance(entP, extP);
1542	pOverall += len;
1543
1544	// use length of rays to approximate volume
1545	switch (cf)
1546	{
1547	case Ray::COINCIDENT:
1548	pBack += len;
1549	pFront += len;
1550	break;
1551	case Ray::BACK:
1552	pBack += len;
1553	break;
1554	case Ray::FRONT:
1555	pFront += len;
1556	break;
1557	case Ray::FRONT_BACK:
1558	{
1559	// find intersection of ray segment with plane
1560	const Vector3 extp = ray->Extrap(maxT);
1561	const float t = candidatePlane.FindT(ray->GetLoc(), extp);
1562
1563	const float newT = t * maxT;
1564	float newLen = Distance(ray->Extrap(newT), extp);
1565
1566	pFront += len - newLen;
1567	pBack += newLen;
1568	}
1569	break;
1570	case Ray::BACK_FRONT:
1571	{
1572	// find intersection of ray segment with plane
1573	const Vector3 extp = ray->Extrap(maxT);
1574	const float t = candidatePlane.FindT(ray->GetLoc(), extp);
1575
1576	const float newT = t * maxT;
1577	float newLen = Distance(ray->Extrap(newT), extp);
1578
1579	pFront += len;
1580	pBack += len - newLen;
1581	}
1582	break;
1583	default:
1584	Debug << "Should not come here 2" << endl;
1585	break;
1586	}
1587	}
1588	}
1589	}
1590
1591	const float raysSize = (float)rays.size() + Limits::Small;
1592
1593	if (mSplitPlaneStrategy & LEAST_RAY_SPLITS)
1594	val += mLeastRaySplitsFactor * sumRaySplits / raysSize;
1595
1596	if (mSplitPlaneStrategy & BALANCED_RAYS)
1597	val += mBalancedRaysFactor * fabs(sumBalancedRays) / raysSize;
1598
1599	float denom = pOverall * (float)pvs * 2.0f + Limits::Small;
1600	if ((mSplitPlaneStrategy & PVS) && area && pvs)
1601	{
1602	val += mPvsFactor * (frontPvs * pFront + (backPvs * pBack)) / denom;
1603
1604	// give penalty to unbalanced split
1605	if (0)
1606	if (((pFront * 0.2 + Limits::Small) > pBack) \|\| (pFront < (pBack * 0.2 + Limits::Small)))
1607	val += 0.5;
1608	}
1609
1610	#ifdef _DEBUG
1611	Debug << "totalpvs: " << pvs << " ptotal: " << pOverall
1612	<< " frontpvs: " << frontPvs << " pFront: " << pFront
1613	<< " backpvs: " << backPvs << " pBack: " << pBack << endl << endl;
1614	#endif
1615
1616	return val;
1617	}
1618
1619	void BspTree::AddObjToPvs(Intersectable *obj,
1620	const int cf,
1621	int &frontPvs,
1622	int &backPvs) const
1623	{
1624	if (!obj)
1625	return;
1626	// TODO: does this really belong to no pvs?
1627	//if (cf == Ray::COINCIDENT) return;
1628
1629	// object belongs to both PVS
1630	const bool bothSides = (cf == Ray::FRONT_BACK) \|\|
1631	(cf == Ray::BACK_FRONT) \|\|
1632	(cf == Ray::COINCIDENT);
1633
1634	if ((cf == Ray::FRONT) \|\| bothSides)
1635	{
1636	if ((obj->mMailbox != sFrontId) &&
1637	(obj->mMailbox != sFrontAndBackId))
1638	{
1639	++ frontPvs;
1640
1641	if (obj->mMailbox == sBackId)
1642	obj->mMailbox = sFrontAndBackId;
1643	else
1644	obj->mMailbox = sFrontId;
1645	}
1646	}
1647
1648	if ((cf == Ray::BACK) \|\| bothSides)
1649	{
1650	if ((obj->mMailbox != sBackId) &&
1651	(obj->mMailbox != sFrontAndBackId))
1652	{
1653	++ backPvs;
1654
1655	if (obj->mMailbox == sFrontId)
1656	obj->mMailbox = sFrontAndBackId;
1657	else
1658	obj->mMailbox = sBackId;
1659	}
1660	}
1661	}
1662
1663	float BspTree::SplitPlaneCost(const Plane3 &candidatePlane,
1664	BspTraversalData &data) const
1665	{
1666	float val = 0;
1667
1668	if (mSplitPlaneStrategy & VERTICAL_AXIS)
1669	{
1670	Vector3 tinyAxis(0,0,0); tinyAxis[mBox.Size().TinyAxis()] = 1.0f;
1671	// we put a penalty on the dot product between the "tiny" vertical axis
1672	// and the split plane axis
1673	val += mVerticalSplitsFactor *
1674	fabs(DotProd(candidatePlane.mNormal, tinyAxis));
1675	}
1676
1677	// the following criteria loop over all polygons to find the cost value
1678	if ((mSplitPlaneStrategy & BALANCED_POLYS) \|\|
1679	(mSplitPlaneStrategy & LEAST_SPLITS) \|\|
1680	(mSplitPlaneStrategy & LARGEST_POLY_AREA) \|\|
1681	(mSplitPlaneStrategy & BALANCED_VIEW_CELLS) \|\|
1682	(mSplitPlaneStrategy & BLOCKED_RAYS))
1683	{
1684	val += SplitPlaneCost(candidatePlane, *data.mPolygons);
1685	}
1686
1687	// the following criteria loop over all rays to find the cost value
1688	if ((mSplitPlaneStrategy & BALANCED_RAYS) \|\|
1689	(mSplitPlaneStrategy & LEAST_RAY_SPLITS) \|\|
1690	(mSplitPlaneStrategy & PVS))
1691	{
1692	val += SplitPlaneCost(candidatePlane, *data.mRays, data.mPvs,
1693	data.mArea, *data.mGeometry);
1694	}
1695
1696	// return linear combination of the sums
1697	return val;
1698	}
1699
1700	void BspTree::CollectLeaves(vector<BspLeaf *> &leaves) const
1701	{
1702	stack<BspNode *> nodeStack;
1703	nodeStack.push(mRoot);
1704
1705	while (!nodeStack.empty())
1706	{
1707	BspNode *node = nodeStack.top();
1708
1709	nodeStack.pop();
1710
1711	if (node->IsLeaf())
1712	{
1713	BspLeaf leaf = (BspLeaf )node;
1714	leaves.push_back(leaf);
1715	}
1716	else
1717	{
1718	BspInterior interior = dynamic_cast<BspInterior >(node);
1719
1720	nodeStack.push(interior->GetBack());
1721	nodeStack.push(interior->GetFront());
1722	}
1723	}
1724	}
1725
1726	AxisAlignedBox3 BspTree::GetBoundingBox() const
1727	{
1728	return mBox;
1729	}
1730
1731	BspNode *BspTree::GetRoot() const
1732	{
1733	return mRoot;
1734	}
1735
1736	void BspTree::EvaluateLeafStats(const BspTraversalData &data)
1737	{
1738	// the node became a leaf -> evaluate stats for leafs
1739	BspLeaf leaf = dynamic_cast<BspLeaf >(data.mNode);
1740
1741	// store maximal and minimal depth
1742	if (data.mDepth > mStat.maxDepth)
1743	mStat.maxDepth = data.mDepth;
1744
1745	if (data.mDepth < mStat.minDepth)
1746	mStat.minDepth = data.mDepth;
1747
1748	// accumulate depth to compute average depth
1749	mStat.accumDepth += data.mDepth;
1750
1751
1752	if (data.mDepth >= mTermMaxDepth)
1753	++ mStat.maxDepthNodes;
1754
1755	if (data.mPvs < mTermMinPvs)
1756	++ mStat.minPvsNodes;
1757
1758	if ((int)data.mRays->size() < mTermMinRays)
1759	++ mStat.minRaysNodes;
1760
1761	if (data.GetAvgRayContribution() > mTermMaxRayContribution)
1762	++ mStat.maxRayContribNodes;
1763
1764	if (data.mGeometry->GetArea() <= mTermMinArea)
1765	++ mStat.minAreaNodes;
1766
1767	#ifdef _DEBUG
1768	Debug << "BSP stats: "
1769	<< "Depth: " << data.mDepth << " (max: " << mTermMaxDepth << "), "
1770	<< "PVS: " << data.mPvs << " (min: " << mTermMinPvs << "), "
1771	<< "Area: " << data.mArea << " (min: " << mTermMinArea << "), "
1772	<< "#polygons: " << (int)data.mPolygons->size() << " (max: " << mTermMinPolys << "), "
1773	<< "#rays: " << (int)data.mRays->size() << " (max: " << mTermMinRays << "), "
1774	<< "#pvs: " << leaf->GetViewCell()->GetPvs().GetSize() << "=, "
1775	<< "#avg ray contrib (pvs): " << (float)data.mPvs / (float)data.mRays->size() << endl;
1776	#endif
1777	}
1778
1779	int BspTree::CastRay(Ray &ray)
1780	{
1781	int hits = 0;
1782
1783	stack<BspRayTraversalData> tStack;
1784
1785	float maxt, mint;
1786
1787	if (!BoundRay(ray, mint, maxt))
1788	return 0;
1789
1790	Intersectable::NewMail();
1791
1792	Vector3 entp = ray.Extrap(mint);
1793	Vector3 extp = ray.Extrap(maxt);
1794
1795	BspNode *node = mRoot;
1796	BspNode *farChild = NULL;
1797
1798	while (1)
1799	{
1800	if (!node->IsLeaf())
1801	{
1802	BspInterior in = (BspInterior ) node;
1803
1804	Plane3 *splitPlane = in->GetPlane();
1805
1806	int entSide = splitPlane->Side(entp);
1807	int extSide = splitPlane->Side(extp);
1808
1809	Vector3 intersection;
1810
1811	if (entSide < 0)
1812	{
1813	node = in->GetBack();
1814
1815	if(extSide <= 0) // plane does not split ray => no far child
1816	continue;
1817
1818	farChild = in->GetFront(); // plane splits ray
1819
1820	} else if (entSide > 0)
1821	{
1822	node = in->GetFront();
1823
1824	if (extSide >= 0) // plane does not split ray => no far child
1825	continue;
1826
1827	farChild = in->GetBack(); // plane splits ray
1828	}
1829	else // ray and plane are coincident
1830	{
1831	// WHAT TO DO IN THIS CASE ?
1832	//break;
1833	node = in->GetFront();
1834	continue;
1835	}
1836
1837	// push data for far child
1838	tStack.push(BspRayTraversalData(farChild, extp, maxt));
1839
1840	// find intersection of ray segment with plane
1841	float t;
1842	extp = splitPlane->FindIntersection(ray.GetLoc(), extp, &t);
1843	maxt *= t;
1844
1845	} else // reached leaf => intersection with view cell
1846	{
1847	BspLeaf leaf = dynamic_cast<BspLeaf >(node);
1848
1849	if (!leaf->mViewCell->Mailed())
1850	{
1851	ray.bspIntersections.push_back(Ray::BspIntersection(maxt, leaf));
1852	leaf->mViewCell->Mail();
1853	++ hits;
1854	}
1855
1856	//-- fetch the next far child from the stack
1857	if (tStack.empty())
1858	break;
1859
1860	entp = extp;
1861	mint = maxt; // NOTE: need this?
1862
1863	if (ray.GetType() == Ray::LINE_SEGMENT && mint > 1.0f)
1864	break;
1865
1866	BspRayTraversalData &s = tStack.top();
1867
1868	node = s.mNode;
1869	extp = s.mExitPoint;
1870	maxt = s.mMaxT;
1871
1872	tStack.pop();
1873	}
1874	}
1875
1876	return hits;
1877	}
1878
1879	bool BspTree::Export(const string filename)
1880	{
1881	Exporter *exporter = Exporter::GetExporter(filename);
1882
1883	if (exporter)
1884	{
1885	exporter->ExportBspTree(*this);
1886	return true;
1887	}
1888
1889	return false;
1890	}
1891
1892	void BspTree::CollectViewCells(ViewCellContainer &viewCells) const
1893	{
1894	stack<BspNode *> nodeStack;
1895	nodeStack.push(mRoot);
1896
1897	ViewCell::NewMail();
1898
1899	while (!nodeStack.empty())
1900	{
1901	BspNode *node = nodeStack.top();
1902	nodeStack.pop();
1903
1904	if (node->IsLeaf())
1905	{
1906	ViewCell viewCell = dynamic_cast<BspLeaf >(node)->mViewCell;
1907
1908	if (!viewCell->Mailed())
1909	{
1910	viewCell->Mail();
1911	viewCells.push_back(viewCell);
1912	}
1913	}
1914	else
1915	{
1916	BspInterior interior = dynamic_cast<BspInterior >(node);
1917
1918	nodeStack.push(interior->mFront);
1919	nodeStack.push(interior->mBack);
1920	}
1921	}
1922	}
1923
1924	void BspTree::EvaluateViewCellsStats(BspViewCellsStatistics &stat) const
1925	{
1926	stat.Reset();
1927
1928	stack<BspNode *> nodeStack;
1929	nodeStack.push(mRoot);
1930
1931	ViewCell::NewMail();
1932
1933	// exclude root cell
1934	mRootCell->Mail();
1935
1936	while (!nodeStack.empty())
1937	{
1938	BspNode *node = nodeStack.top();
1939	nodeStack.pop();
1940
1941	if (node->IsLeaf())
1942	{
1943	++ stat.bspLeaves;
1944
1945	BspViewCell viewCell = dynamic_cast<BspLeaf >(node)->mViewCell;
1946
1947	if (!viewCell->Mailed())
1948	{
1949	viewCell->Mail();
1950
1951	++ stat.viewCells;
1952	const int pvsSize = viewCell->GetPvs().GetSize();
1953
1954	stat.pvs += pvsSize;
1955
1956	if (pvsSize < 1)
1957	++ stat.emptyPvs;
1958
1959	if (pvsSize > stat.maxPvs)
1960	stat.maxPvs = pvsSize;
1961
1962	if (pvsSize < stat.minPvs)
1963	stat.minPvs = pvsSize;
1964
1965	if ((int)viewCell->mBspLeaves.size() > stat.maxBspLeaves)
1966	stat.maxBspLeaves = (int)viewCell->mBspLeaves.size();
1967	}
1968	}
1969	else
1970	{
1971	BspInterior interior = dynamic_cast<BspInterior >(node);
1972
1973	nodeStack.push(interior->mFront);
1974	nodeStack.push(interior->mBack);
1975	}
1976	}
1977	}
1978
1979	bool BspTree::MergeViewCells(BspLeaf front, BspLeaf back) const
1980	{
1981	BspViewCell *viewCell =
1982	dynamic_cast<BspViewCell >(ViewCell::Merge(front->mViewCell, *back->mViewCell));
1983
1984	if (!viewCell)
1985	return false;
1986
1987	// change view cells of all leaves associated with the
1988	// previous view cells
1989
1990	BspViewCell *fVc = front->mViewCell;
1991	BspViewCell *bVc = back->mViewCell;
1992
1993	vector<BspLeaf *> fLeaves = fVc->mBspLeaves;
1994	vector<BspLeaf *> bLeaves = bVc->mBspLeaves;
1995
1996	vector<BspLeaf *>::const_iterator it;
1997
1998	for (it = fLeaves.begin(); it != fLeaves.end(); ++ it)
1999	{
2000	(*it)->SetViewCell(viewCell);
2001	viewCell->mBspLeaves.push_back(*it);
2002	}
2003	for (it = bLeaves.begin(); it != bLeaves.end(); ++ it)
2004	{
2005	(*it)->SetViewCell(viewCell);
2006	viewCell->mBspLeaves.push_back(*it);
2007	}
2008
2009	DEL_PTR(fVc);
2010	DEL_PTR(bVc);
2011
2012	return true;
2013	}
2014
2015	bool BspTree::ShouldMerge(BspLeaf front, BspLeaf back) const
2016	{
2017	ViewCell *fvc = front->mViewCell;
2018	ViewCell *bvc = back->mViewCell;
2019
2020	if ((fvc == mRootCell) \|\| (bvc == mRootCell) \|\| (fvc == bvc))
2021	return false;
2022
2023	int fdiff = fvc->GetPvs().Diff(bvc->GetPvs());
2024
2025	if (fvc->GetPvs().GetSize() + fdiff < mMaxPvs)
2026	{
2027	if ((fvc->GetPvs().GetSize() < mMinPvs) \|\|
2028	(bvc->GetPvs().GetSize() < mMinPvs) \|\|
2029	((fdiff < mMinPvsDif) && (bvc->GetPvs().Diff(fvc->GetPvs()) < mMinPvsDif)))
2030	{
2031	return true;
2032	}
2033	}
2034
2035	return false;
2036	}
2037
2038
2039	BspTreeStatistics &BspTree::GetStat()
2040	{
2041	return mStat;
2042	}
2043
2044	float BspTree::AccumulatedRayLength(BoundedRayContainer &rays) const
2045	{
2046	float len = 0;
2047
2048	BoundedRayContainer::const_iterator it, it_end = rays.end();
2049
2050	for (it = rays.begin(); it != it_end; ++ it)
2051	{
2052	len += SqrDistance((it)->mRay->Extrap((it)->mMinT),
2053	(it)->mRay->Extrap((it)->mMaxT));
2054	}
2055
2056	return len;
2057	}
2058
2059	int BspTree::SplitRays(const Plane3 &plane,
2060	BoundedRayContainer &rays,
2061	BoundedRayContainer &frontRays,
2062	BoundedRayContainer &backRays)
2063	{
2064	int splits = 0;
2065
2066	while (!rays.empty())
2067	{
2068	BoundedRay *bRay = rays.back();
2069	Ray *ray = bRay->mRay;
2070	float minT = bRay->mMinT;
2071	float maxT = bRay->mMaxT;
2072
2073	rays.pop_back();
2074
2075	Vector3 entP, extP;
2076
2077	const int cf =
2078	ray->ClassifyPlane(plane, minT, maxT, entP, extP);
2079
2080	// set id to ray classification
2081	ray->SetId(cf);
2082
2083	switch (cf)
2084	{
2085	case Ray::COINCIDENT: // TODO: should really discard ray?
2086	frontRays.push_back(bRay);
2087	//DEL_PTR(bRay);
2088	break;
2089	case Ray::BACK:
2090	backRays.push_back(bRay);
2091	break;
2092	case Ray::FRONT:
2093	frontRays.push_back(bRay);
2094	break;
2095	case Ray::FRONT_BACK:
2096	{
2097	// find intersection of ray segment with plane
2098	const float t = plane.FindT(ray->GetLoc(), extP);
2099
2100	const float newT = t * maxT;
2101
2102	frontRays.push_back(new BoundedRay(ray, minT, newT));
2103	backRays.push_back(new BoundedRay(ray, newT, maxT));
2104
2105	DEL_PTR(bRay);
2106	}
2107	break;
2108	case Ray::BACK_FRONT:
2109	{
2110	// find intersection of ray segment with plane
2111	const float t = plane.FindT(ray->GetLoc(), extP);
2112	const float newT = t * bRay->mMaxT;
2113
2114	backRays.push_back(new BoundedRay(ray, bRay->mMinT, newT));
2115	frontRays.push_back(new BoundedRay(ray, newT, bRay->mMaxT));
2116	DEL_PTR(bRay);
2117
2118	++ splits;
2119	}
2120	break;
2121	default:
2122	Debug << "Should not come here 4" << endl;
2123	break;
2124	}
2125	}
2126
2127	return splits;
2128	}
2129
2130	void BspTree::ExtractHalfSpaces(BspNode *n, vector<Plane3> &halfSpaces) const
2131	{
2132	BspNode *lastNode;
2133	do
2134	{
2135	lastNode = n;
2136
2137	// want to get planes defining geometry of this node => don't take
2138	// split plane of node itself
2139	n = n->GetParent();
2140
2141	if (n)
2142	{
2143	BspInterior interior = dynamic_cast<BspInterior >(n);
2144	Plane3 halfSpace = dynamic_cast<BspInterior >(interior)->GetPlane();
2145
2146	if (interior->mFront != lastNode)
2147	halfSpace.ReverseOrientation();
2148
2149	halfSpaces.push_back(halfSpace);
2150	}
2151	}
2152	while (n);
2153	}
2154
2155	void BspTree::ConstructGeometry(BspNode *n, BspNodeGeometry &cell) const
2156	{
2157	PolygonContainer polys;
2158	ConstructGeometry(n, polys);
2159	cell.mPolys = polys;
2160	}
2161
2162	void BspTree::ConstructGeometry(BspViewCell *vc, PolygonContainer &cell) const
2163	{
2164	vector<BspLeaf *> leaves = vc->mBspLeaves;
2165
2166	vector<BspLeaf *>::const_iterator it, it_end = leaves.end();
2167
2168	for (it = leaves.begin(); it != it_end; ++ it)
2169	ConstructGeometry(*it, cell);
2170	}
2171
2172
2173	void BspTree::ConstructGeometry(BspNode *n, PolygonContainer &cell) const
2174	{
2175	vector<Plane3> halfSpaces;
2176	ExtractHalfSpaces(n, halfSpaces);
2177
2178	PolygonContainer candidatePolys;
2179
2180	// bounded planes are added to the polygons (reverse polygons
2181	// as they have to be outfacing
2182	for (int i = 0; i < (int)halfSpaces.size(); ++ i)
2183	{
2184	Polygon3 *p = GetBoundingBox().CrossSection(halfSpaces[i]);
2185
2186	if (p->Valid())
2187	{
2188	candidatePolys.push_back(p->CreateReversePolygon());
2189	DEL_PTR(p);
2190	}
2191	}
2192
2193	// add faces of bounding box (also could be faces of the cell)
2194	for (int i = 0; i < 6; ++ i)
2195	{
2196	VertexContainer vertices;
2197
2198	for (int j = 0; j < 4; ++ j)
2199	vertices.push_back(mBox.GetFace(i).mVertices[j]);
2200
2201	candidatePolys.push_back(new Polygon3(vertices));
2202	}
2203
2204	for (int i = 0; i < (int)candidatePolys.size(); ++ i)
2205	{
2206	// polygon is split by all other planes
2207	for (int j = 0; (j < (int)halfSpaces.size()) && candidatePolys[i]; ++ j)
2208	{
2209	if (i == j) // polygon and plane are coincident
2210	continue;
2211
2212	VertexContainer splitPts;
2213	Polygon3 frontPoly, backPoly;
2214
2215	const int cf = candidatePolys[i]->ClassifyPlane(halfSpaces[j]);
2216
2217	switch (cf)
2218	{
2219	case Polygon3::SPLIT:
2220	frontPoly = new Polygon3();
2221	backPoly = new Polygon3();
2222
2223	candidatePolys[i]->Split(halfSpaces[j],
2224	*frontPoly,
2225	*backPoly);
2226
2227	DEL_PTR(candidatePolys[i]);
2228
2229	if (frontPoly->Valid())
2230	candidatePolys[i] = frontPoly;
2231	else
2232	DEL_PTR(frontPoly);
2233
2234	DEL_PTR(backPoly);
2235	break;
2236	case Polygon3::BACK_SIDE:
2237	DEL_PTR(candidatePolys[i]);
2238	break;
2239	// just take polygon as it is
2240	case Polygon3::FRONT_SIDE:
2241	case Polygon3::COINCIDENT:
2242	default:
2243	break;
2244	}
2245	}
2246
2247	if (candidatePolys[i])
2248	cell.push_back(candidatePolys[i]);
2249	}
2250	}
2251
2252
2253	int BspTree::FindNeighbors(BspNode n, vector<BspLeaf > &neighbors,
2254	const bool onlyUnmailed) const
2255	{
2256	PolygonContainer cell;
2257
2258	ConstructGeometry(n, cell);
2259
2260	stack<BspNode *> nodeStack;
2261	nodeStack.push(mRoot);
2262
2263	// planes needed to verify that we found neighbor leaf.
2264	vector<Plane3> halfSpaces;
2265	ExtractHalfSpaces(n, halfSpaces);
2266
2267	while (!nodeStack.empty())
2268	{
2269	BspNode *node = nodeStack.top();
2270	nodeStack.pop();
2271
2272	if (node->IsLeaf())
2273	{
2274	if (node != n && (!onlyUnmailed \|\| !node->Mailed()))
2275	{
2276	// test all planes of current node if candidate really
2277	// is neighbour
2278	PolygonContainer neighborCandidate;
2279	ConstructGeometry(node, neighborCandidate);
2280
2281	bool isAdjacent = true;
2282	for (int i = 0; (i < halfSpaces.size()) && isAdjacent; ++ i)
2283	{
2284	const int cf =
2285	Polygon3::ClassifyPlane(neighborCandidate, halfSpaces[i]);
2286
2287	if (cf == Polygon3::BACK_SIDE)
2288	isAdjacent = false;
2289	}
2290
2291	if (isAdjacent)
2292	neighbors.push_back(dynamic_cast<BspLeaf *>(node));
2293
2294	CLEAR_CONTAINER(neighborCandidate);
2295	}
2296	}
2297	else
2298	{
2299	BspInterior interior = dynamic_cast<BspInterior >(node);
2300
2301	const int cf = Polygon3::ClassifyPlane(cell, interior->mPlane);
2302
2303	if (cf == Polygon3::FRONT_SIDE)
2304	nodeStack.push(interior->mFront);
2305	else
2306	if (cf == Polygon3::BACK_SIDE)
2307	nodeStack.push(interior->mBack);
2308	else
2309	{
2310	// random decision
2311	nodeStack.push(interior->mBack);
2312	nodeStack.push(interior->mFront);
2313	}
2314	}
2315	}
2316
2317	CLEAR_CONTAINER(cell);
2318	return (int)neighbors.size();
2319	}
2320
2321	BspLeaf *BspTree::GetRandomLeaf(const Plane3 &halfspace)
2322	{
2323	stack<BspNode *> nodeStack;
2324	nodeStack.push(mRoot);
2325
2326	int mask = rand();
2327
2328	while (!nodeStack.empty())
2329	{
2330	BspNode *node = nodeStack.top();
2331	nodeStack.pop();
2332
2333	if (node->IsLeaf())
2334	{
2335	return dynamic_cast<BspLeaf *>(node);
2336	}
2337	else
2338	{
2339	BspInterior interior = dynamic_cast<BspInterior >(node);
2340
2341	BspNode *next;
2342
2343	PolygonContainer cell;
2344
2345	// todo: not very efficient: constructs full cell everytime
2346	ConstructGeometry(interior, cell);
2347
2348	const int cf = Polygon3::ClassifyPlane(cell, halfspace);
2349
2350	if (cf == Polygon3::BACK_SIDE)
2351	next = interior->mFront;
2352	else
2353	if (cf == Polygon3::FRONT_SIDE)
2354	next = interior->mFront;
2355	else
2356	{
2357	// random decision
2358	if (mask & 1)
2359	next = interior->mBack;
2360	else
2361	next = interior->mFront;
2362	mask = mask >> 1;
2363	}
2364
2365	nodeStack.push(next);
2366	}
2367	}
2368
2369	return NULL;
2370	}
2371
2372	BspLeaf *BspTree::GetRandomLeaf(const bool onlyUnmailed)
2373	{
2374	stack<BspNode *> nodeStack;
2375
2376	nodeStack.push(mRoot);
2377
2378	int mask = rand();
2379
2380	while (!nodeStack.empty())
2381	{
2382	BspNode *node = nodeStack.top();
2383	nodeStack.pop();
2384
2385	if (node->IsLeaf())
2386	{
2387	if ( (!onlyUnmailed \|\| !node->Mailed()) )
2388	return dynamic_cast<BspLeaf *>(node);
2389	}
2390	else
2391	{
2392	BspInterior interior = dynamic_cast<BspInterior >(node);
2393
2394	// random decision
2395	if (mask & 1)
2396	nodeStack.push(interior->mBack);
2397	else
2398	nodeStack.push(interior->mFront);
2399
2400	mask = mask >> 1;
2401	}
2402	}
2403
2404	return NULL;
2405	}
2406
2407	int BspTree::ComputePvsSize(const BoundedRayContainer &rays) const
2408	{
2409	int pvsSize = 0;
2410
2411	BoundedRayContainer::const_iterator rit, rit_end = rays.end();
2412
2413	Intersectable::NewMail();
2414
2415	for (rit = rays.begin(); rit != rays.end(); ++ rit)
2416	{
2417	Ray ray = (rit)->mRay;
2418
2419	if (!ray->intersections.empty())
2420	{
2421	if (!ray->intersections[0].mObject->Mailed())
2422	{
2423	ray->intersections[0].mObject->Mail();
2424	++ pvsSize;
2425	}
2426	}
2427	if (ray->sourceObject.mObject)
2428	{
2429	if (!ray->sourceObject.mObject->Mailed())
2430	{
2431	ray->sourceObject.mObject->Mail();
2432	++ pvsSize;
2433	}
2434	}
2435	}
2436
2437	return pvsSize;
2438	}
2439
2440	/*************************************************************
2441	* BspNodeGeometry Implementation *
2442	*************************************************************/
2443
2444	BspNodeGeometry::~BspNodeGeometry()
2445	{
2446	CLEAR_CONTAINER(mPolys);
2447	}
2448
2449	float BspNodeGeometry::GetArea() const
2450	{
2451	return Polygon3::GetArea(mPolys);
2452	}
2453
2454	void BspNodeGeometry::SplitGeometry(BspNodeGeometry &front,
2455	BspNodeGeometry &back,
2456	const BspTree &tree,
2457	const Plane3 &splitPlane) const
2458	{
2459	// get cross section of new polygon
2460	Polygon3 *planePoly = tree.GetBoundingBox().CrossSection(splitPlane);
2461
2462	planePoly = SplitPolygon(planePoly, tree);
2463
2464	//-- plane poly splits all other cell polygons
2465	for (int i = 0; i < (int)mPolys.size(); ++ i)
2466	{
2467	const int cf = mPolys[i]->ClassifyPlane(splitPlane, 0.00001f);
2468
2469	// split new polygon with all previous planes
2470	switch (cf)
2471	{
2472	case Polygon3::SPLIT:
2473	{
2474	Polygon3 *poly = new Polygon3(mPolys[i]->mVertices);
2475
2476	Polygon3 *frontPoly = new Polygon3();
2477	Polygon3 *backPoly = new Polygon3();
2478
2479	poly->Split(splitPlane, frontPoly, backPoly);
2480
2481	DEL_PTR(poly);
2482
2483	if (frontPoly->Valid())
2484	front.mPolys.push_back(frontPoly);
2485	if (backPoly->Valid())
2486	back.mPolys.push_back(backPoly);
2487	}
2488
2489	break;
2490	case Polygon3::BACK_SIDE:
2491	back.mPolys.push_back(new Polygon3(mPolys[i]->mVertices));
2492	break;
2493	case Polygon3::FRONT_SIDE:
2494	front.mPolys.push_back(new Polygon3(mPolys[i]->mVertices));
2495	break;
2496	case Polygon3::COINCIDENT:
2497	//front.mPolys.push_back(CreateReversePolygon(mPolys[i]));
2498	back.mPolys.push_back(new Polygon3(mPolys[i]->mVertices));
2499	break;
2500	default:
2501	break;
2502	}
2503	}
2504
2505	//-- finally add the new polygon to the child cells
2506	if (planePoly)
2507	{
2508	// add polygon with normal pointing into positive half space to back cell
2509	back.mPolys.push_back(planePoly);
2510	// add polygon with reverse orientation to front cell
2511	front.mPolys.push_back(planePoly->CreateReversePolygon());
2512	}
2513
2514	//Debug << "returning new geometry " << mPolys.size() << " f: " << front.mPolys.size() << " b: " << back.mPolys.size() << endl;
2515	//Debug << "old area " << GetArea() << " f: " << front.GetArea() << " b: " << back.GetArea() << endl;
2516	}
2517
2518	Polygon3 BspNodeGeometry::SplitPolygon(Polygon3 planePoly,
2519	const BspTree &tree) const
2520	{
2521	// polygon is split by all other planes
2522	for (int i = 0; (i < (int)mPolys.size()) && planePoly; ++ i)
2523	{
2524	Plane3 plane = mPolys[i]->GetSupportingPlane();
2525
2526	const int cf =
2527	planePoly->ClassifyPlane(plane, 0.00001f);
2528
2529	// split new polygon with all previous planes
2530	switch (cf)
2531	{
2532	case Polygon3::SPLIT:
2533	{
2534	Polygon3 *frontPoly = new Polygon3();
2535	Polygon3 *backPoly = new Polygon3();
2536
2537	planePoly->Split(plane, frontPoly, backPoly);
2538	DEL_PTR(planePoly);
2539
2540	if (backPoly->Valid())
2541	planePoly = backPoly;
2542	else
2543	DEL_PTR(backPoly);
2544	}
2545	break;
2546	case Polygon3::FRONT_SIDE:
2547	DEL_PTR(planePoly);
2548	break;
2549	// polygon is taken as it is
2550	case Polygon3::BACK_SIDE:
2551	case Polygon3::COINCIDENT:
2552	default:
2553	break;
2554	}
2555	}
2556
2557	return planePoly;
2558	}
2559
2560	void BspViewCellsStatistics::Print(ostream &app) const
2561	{
2562	app << "===== BspViewCells statistics ===============\n";
2563
2564	app << setprecision(4);
2565
2566	//app << "#N_CTIME ( Construction time [s] )\n" << Time() << " \n";
2567
2568	app << "#N_OVERALLPVS ( objects in PVS )\n" << pvs << endl;
2569
2570	app << "#N_PMAXPVS ( largest PVS )\n" << maxPvs << endl;
2571
2572	app << "#N_PMINPVS ( smallest PVS )\n" << minPvs << endl;
2573
2574	app << "#N_PAVGPVS ( average PVS )\n" << AvgPvs() << endl;
2575
2576	app << "#N_PEMPTYPVS ( view cells with PVS smaller 2 )\n" << emptyPvs << endl;
2577
2578	app << "#N_VIEWCELLS ( number of view cells)\n" << viewCells << endl;
2579
2580	app << "#N_AVGBSPLEAVES (average number of BSP leaves per view cell )\n" << AvgBspLeaves() << endl;
2581
2582	app << "#N_MAXBSPLEAVES ( maximal number of BSP leaves per view cell )\n" << maxBspLeaves << endl;
2583
2584	app << "===== END OF BspViewCells statistics ==========\n";
2585	}

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