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source: trunk/VUT/GtpVisibilityPreprocessor/src/ViewCellBsp.cpp @ 483

Revision 483, 66.0 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
12	#include "Exporter.h"
13	#include "Plane3.h"
14
15	//-- static members
16
17	int BspNode::sMailId = 1;
18
19	/** Evaluates split plane classification with respect to the plane's
20	contribution for a minimum number splits in the tree.
21	*/
22	const float BspTree::sLeastPolySplitsTable[] = {0, 0, 1, 0};
23	/** Evaluates split plane classification with respect to the plane's
24	contribution for a balanced tree.
25	*/
26	const float BspTree::sBalancedPolysTable[] = {1, -1, 0, 0};
27
28	/** Evaluates split plane classification with respect to the plane's
29	contribution for a minimum number of ray splits.
30	*/
31	const float BspTree::sLeastRaySplitsTable[] = {0, 0, 1, 1, 0};
32	/** Evaluates split plane classification with respect to the plane's
33	contribution for balanced rays.
34	*/
35	const float BspTree::sBalancedRaysTable[] = {1, -1, 0, 0, 0};
36
37	int BspTree::sFrontId = 0;
38	int BspTree::sBackId = 0;
39	int BspTree::sFrontAndBackId = 0;
40
41	/****************************************************************/
42	/* class BspNode implementation */
43	/****************************************************************/
44
45	BspNode::BspNode():
46	mParent(NULL)
47	{}
48
49	BspNode::BspNode(BspInterior *parent):
50	mParent(parent)
51	{}
52
53
54	bool BspNode::IsRoot() const
55	{
56	return mParent == NULL;
57	}
58
59
60	BspInterior *BspNode::GetParent()
61	{
62	return mParent;
63	}
64
65
66	void BspNode::SetParent(BspInterior *parent)
67	{
68	mParent = parent;
69	}
70
71
72	bool BspNode::IsSibling(BspNode *n) const
73	{
74	return ((this != n) && mParent &&
75	(mParent->GetFront() == n) \|\| (mParent->GetBack() == n));
76	}
77
78	int BspNode::GetDepth() const
79	{
80	int depth = 0;
81	BspNode *p = mParent;
82
83	while (p)
84	{
85	p = p->mParent;
86	++ depth;
87	}
88
89	return depth;
90	}
91
92	/****************************************************************/
93	/* class BspInterior implementation */
94	/****************************************************************/
95
96
97	BspInterior::BspInterior(const Plane3 &plane):
98	mPlane(plane), mFront(NULL), mBack(NULL)
99	{}
100
101	BspInterior::~BspInterior()
102	{
103	DEL_PTR(mFront);
104	DEL_PTR(mBack);
105	}
106
107	bool BspInterior::IsLeaf() const
108	{
109	return false;
110	}
111
112	BspNode *BspInterior::GetBack()
113	{
114	return mBack;
115	}
116
117	BspNode *BspInterior::GetFront()
118	{
119	return mFront;
120	}
121
122	Plane3 BspInterior::GetPlane() const
123	{
124	return mPlane;
125	}
126
127	void BspInterior::ReplaceChildLink(BspNode oldChild, BspNode newChild)
128	{
129	if (mBack == oldChild)
130	mBack = newChild;
131	else
132	mFront = newChild;
133	}
134
135	void BspInterior::SetupChildLinks(BspNode b, BspNode f)
136	{
137	mBack = b;
138	mFront = f;
139	}
140
141	/****************************************************************/
142	/* class BspLeaf implementation */
143	/****************************************************************/
144
145
146	BspLeaf::BspLeaf(): mViewCell(NULL)
147	{
148	}
149
150
151	BspLeaf::BspLeaf(BspViewCell *viewCell):
152	mViewCell(viewCell)
153	{
154	}
155
156
157	BspLeaf::BspLeaf(BspInterior *parent):
158	BspNode(parent), mViewCell(NULL)
159	{}
160
161
162
163	BspLeaf::BspLeaf(BspInterior parent, BspViewCell viewCell):
164	BspNode(parent), mViewCell(viewCell)
165	{
166	}
167
168	BspViewCell *BspLeaf::GetViewCell() const
169	{
170	return mViewCell;
171	}
172
173	void BspLeaf::SetViewCell(BspViewCell *viewCell)
174	{
175	mViewCell = viewCell;
176	}
177
178	bool BspLeaf::IsLeaf() const
179	{
180	return true;
181	}
182
183
184	/****************************************************************/
185	/* class BspTree implementation */
186	/****************************************************************/
187
188	BspTree::BspTree():
189	mRoot(NULL),
190	mPvsUseArea(true),
191	mGenerateViewCells(true)
192	{
193	Randomize(); // initialise random generator for heuristics
194
195	// the view cell corresponding to unbounded space
196	mRootCell = new BspViewCell();
197
198	//-- termination criteria for autopartition
199	environment->GetIntValue("BspTree.Termination.maxDepth", mTermMaxDepth);
200	environment->GetIntValue("BspTree.Termination.minPvs", mTermMinPvs);
201	environment->GetIntValue("BspTree.Termination.minPolygons", mTermMinPolys);
202	environment->GetIntValue("BspTree.Termination.minRays", mTermMinRays);
203	environment->GetFloatValue("BspTree.Termination.minArea", mTermMinArea);
204	environment->GetFloatValue("BspTree.Termination.maxRayContribution", mTermMaxRayContribution);
205	environment->GetFloatValue("BspTree.Termination.minAccRayLenght", mTermMinAccRayLength);
206
207	//-- factors for bsp tree split plane heuristics
208	environment->GetFloatValue("BspTree.Factor.verticalSplits", mVerticalSplitsFactor);
209	environment->GetFloatValue("BspTree.Factor.largestPolyArea", mLargestPolyAreaFactor);
210	environment->GetFloatValue("BspTree.Factor.blockedRays", mBlockedRaysFactor);
211	environment->GetFloatValue("BspTree.Factor.leastRaySplits", mLeastRaySplitsFactor);
212	environment->GetFloatValue("BspTree.Factor.balancedRays", mBalancedRaysFactor);
213	environment->GetFloatValue("BspTree.Factor.pvs", mPvsFactor);
214	environment->GetFloatValue("BspTree.Factor.leastSplits" , mLeastSplitsFactor);
215	environment->GetFloatValue("BspTree.Factor.balancedPolys", mBalancedPolysFactor);
216	environment->GetFloatValue("BspTree.Factor.balancedViewCells", mBalancedViewCellsFactor);
217	environment->GetFloatValue("BspTree.Termination.ct_div_ci", mCtDivCi);
218
219	//-- termination criteria for axis aligned split
220	environment->GetFloatValue("BspTree.Termination.AxisAligned.ct_div_ci", mAxisAlignedCtDivCi);
221	environment->GetFloatValue("BspTree.Termination.maxCostRatio", mMaxCostRatio);
222	environment->GetIntValue("BspTree.Termination.AxisAligned.minPolys",
223	mTermMinPolysForAxisAligned);
224	environment->GetIntValue("BspTree.Termination.AxisAligned.minRays",
225	mTermMinRaysForAxisAligned);
226	environment->GetIntValue("BspTree.Termination.AxisAligned.minObjects",
227	mTermMinObjectsForAxisAligned);
228	//-- partition criteria
229	environment->GetIntValue("BspTree.maxPolyCandidates", mMaxPolyCandidates);
230	environment->GetIntValue("BspTree.maxRayCandidates", mMaxRayCandidates);
231	environment->GetIntValue("BspTree.splitPlaneStrategy", mSplitPlaneStrategy);
232	environment->GetFloatValue("BspTree.AxisAligned.splitBorder", mSplitBorder);
233	environment->GetIntValue("BspTree.maxTests", mMaxTests);
234
235	environment->GetFloatValue("BspTree.Construction.epsilon", mEpsilon);
236
237	Debug << "BSP max depth: " << mTermMaxDepth << endl;
238	Debug << "BSP min PVS: " << mTermMinPvs << endl;
239	Debug << "BSP min area: " << mTermMinArea << endl;
240	Debug << "BSP max polys: " << mTermMinPolys << endl;
241	Debug << "BSP max rays: " << mTermMinRays << endl;
242	Debug << "BSP max polygon candidates: " << mMaxPolyCandidates << endl;
243	Debug << "BSP max plane candidates: " << mMaxRayCandidates << endl;
244
245	Debug << "Split plane strategy: ";
246	if (mSplitPlaneStrategy & RANDOM_POLYGON)
247	Debug << "random polygon ";
248	if (mSplitPlaneStrategy & AXIS_ALIGNED)
249	Debug << "axis aligned ";
250	if (mSplitPlaneStrategy & LEAST_SPLITS)
251	Debug << "least splits ";
252	if (mSplitPlaneStrategy & BALANCED_POLYS)
253	Debug << "balanced polygons ";
254	if (mSplitPlaneStrategy & BALANCED_VIEW_CELLS)
255	Debug << "balanced view cells ";
256	if (mSplitPlaneStrategy & LARGEST_POLY_AREA)
257	Debug << "largest polygon area ";
258	if (mSplitPlaneStrategy & VERTICAL_AXIS)
259	Debug << "vertical axis ";
260	if (mSplitPlaneStrategy & BLOCKED_RAYS)
261	Debug << "blocked rays ";
262	if (mSplitPlaneStrategy & LEAST_RAY_SPLITS)
263	Debug << "least ray splits ";
264	if (mSplitPlaneStrategy & BALANCED_RAYS)
265	Debug << "balanced rays ";
266	if (mSplitPlaneStrategy & PVS)
267	Debug << "pvs";
268
269	Debug << endl;
270	}
271
272
273	const BspTreeStatistics &BspTree::GetStatistics() const
274	{
275	return mStat;
276	}
277
278
279	int BspTree::SplitPolygons(const Plane3 &plane,
280	PolygonContainer &polys,
281	PolygonContainer &frontPolys,
282	PolygonContainer &backPolys,
283	PolygonContainer &coincident) const
284	{
285	int splits = 0;
286
287	#ifdef _Debug
288	Debug << "splitting polygons of node " << this << " with plane " << mPlane << endl;
289	#endif
290	while (!polys.empty())
291	{
292	Polygon3 *poly = polys.back();
293	polys.pop_back();
294
295	//Debug << "New polygon with plane: " << poly->GetSupportingPlane() << "\n";
296
297	// classify polygon
298	const int cf = poly->ClassifyPlane(plane, mEpsilon);
299
300	switch (cf)
301	{
302	case Polygon3::COINCIDENT:
303	coincident.push_back(poly);
304	break;
305	case Polygon3::FRONT_SIDE:
306	frontPolys.push_back(poly);
307	break;
308	case Polygon3::BACK_SIDE:
309	backPolys.push_back(poly);
310	break;
311	case Polygon3::SPLIT:
312	{
313	Polygon3 *front_piece = new Polygon3(poly->mParent);
314	Polygon3 *back_piece = new Polygon3(poly->mParent);
315
316	//-- split polygon into front and back part
317	poly->Split(plane,
318	*front_piece,
319	*back_piece,
320	mEpsilon);
321
322	++ splits; // increase number of splits
323
324	//-- inherit rays from parent polygon for blocked ray criterium
325	poly->InheritRays(front_piece, back_piece);
326
327	// check if polygons still valid
328	if (front_piece->Valid(mEpsilon))
329	frontPolys.push_back(front_piece);
330	else
331	DEL_PTR(front_piece);
332
333	if (back_piece->Valid(mEpsilon))
334	backPolys.push_back(back_piece);
335	else
336	DEL_PTR(back_piece);
337
338	#ifdef _DEBUG
339	Debug << "split " << poly << endl << front_piece << endl << *back_piece << endl;
340	#endif
341	DEL_PTR(poly);
342	}
343	break;
344	default:
345	Debug << "SHOULD NEVER COME HERE\n";
346	break;
347	}
348	}
349
350	return splits;
351	}
352
353
354	void BspTreeStatistics::Print(ostream &app) const
355	{
356	app << "===== BspTree statistics ===============\n";
357
358	app << setprecision(4);
359
360	app << "#N_CTIME ( Construction time [s] )\n" << Time() << " \n";
361
362	app << "#N_NODES ( Number of nodes )\n" << nodes << "\n";
363
364	app << "#N_INTERIORS ( Number of interior nodes )\n" << Interior() << "\n";
365
366	app << "#N_LEAVES ( Number of leaves )\n" << Leaves() << "\n";
367
368	app << "#N_SPLITS ( Number of splits )\n" << splits << "\n";
369
370	app << "#N_PMAXDEPTHLEAVES ( Percentage of leaves at maximum depth )\n"
371	<< maxDepthNodes * 100 / (double)Leaves() << endl;
372
373	app << "#N_PMINPVSLEAVES ( Percentage of leaves with mininimal PVS )\n"
374	<< minPvsNodes * 100 / (double)Leaves() << endl;
375
376	app << "#N_PMINRAYSLEAVES ( Percentage of leaves with minimal number of rays)\n"
377	<< minRaysNodes * 100 / (double)Leaves() << endl;
378
379	app << "#N_MAXCOSTNODES ( Percentage of leaves with terminated because of max cost ratio )\n"
380	<< maxCostNodes * 100 / (double)Leaves() << endl;
381
382	app << "#N_PMINAREALEAVES ( Percentage of leaves with mininum area )\n"
383	<< minAreaNodes * 100 / (double)Leaves() << endl;
384
385	app << "#N_PMAXRAYCONTRIBLEAVES ( Percentage of leaves with maximal ray contribution )\n"
386	<< maxRayContribNodes * 100 / (double)Leaves() << endl;
387
388	app << "#N_PMAXDEPTH ( Maximal reached depth )\n" << maxDepth << endl;
389
390	app << "#N_PMINDEPTH ( Minimal reached depth )\n" << minDepth << endl;
391
392	app << "#AVGDEPTH ( average depth )\n" << AvgDepth() << endl;
393
394	app << "#N_INPUT_POLYGONS (number of input polygons )\n" << polys << endl;
395
396	//app << "#N_PVS: " << pvs << endl;
397
398	app << "#N_ROUTPUT_INPUT_POLYGONS ( ratio polygons after subdivision / input polygons )\n" <<
399	(polys + splits) / (double)polys << endl;
400
401	app << "===== END OF BspTree statistics ==========\n";
402	}
403
404
405	BspTree::~BspTree()
406	{
407	DEL_PTR(mRoot);
408	DEL_PTR(mRootCell);
409	}
410
411	BspViewCell *BspTree::GetRootCell() const
412	{
413	return mRootCell;
414	}
415
416	void BspTree::InsertViewCell(ViewCell *viewCell)
417	{
418	PolygonContainer *polys = new PolygonContainer();
419
420	// don't generate new view cell, insert this one
421	mGenerateViewCells = false;
422	// extract polygons that guide the split process
423	mStat.polys += AddMeshToPolygons(viewCell->GetMesh(), *polys, viewCell);
424	mBox.Include(viewCell->GetBox()); // add to BSP aabb
425
426	InsertPolygons(polys);
427	}
428
429	void BspTree::InsertPolygons(PolygonContainer *polys)
430	{
431	BspTraversalStack tStack;
432
433	// traverse existing tree or create new tree
434	if (!mRoot)
435	mRoot = new BspLeaf();
436
437	tStack.push(BspTraversalData(mRoot,
438	polys,
439	0,
440	mRootCell,
441	new BoundedRayContainer(),
442	0,
443	mBox.SurfaceArea(),
444	new BspNodeGeometry()));
445
446	while (!tStack.empty())
447	{
448	// filter polygons donw the tree
449	BspTraversalData tData = tStack.top();
450	tStack.pop();
451
452	if (!tData.mNode->IsLeaf())
453	{
454	BspInterior interior = dynamic_cast<BspInterior >(tData.mNode);
455
456	//-- filter view cell polygons down the tree until a leaf is reached
457	if (!tData.mPolygons->empty())
458	{
459	PolygonContainer *frontPolys = new PolygonContainer();
460	PolygonContainer *backPolys = new PolygonContainer();
461	PolygonContainer coincident;
462
463	int splits = 0;
464
465	// split viewcell polygons with respect to split plane
466	splits += SplitPolygons(interior->GetPlane(),
467	*tData.mPolygons,
468	*frontPolys,
469	*backPolys,
470	coincident);
471
472	// extract view cells associated with the split polygons
473	ViewCell *frontViewCell = mRootCell;
474	ViewCell *backViewCell = mRootCell;
475
476	BspTraversalData frontData(interior->GetFront(),
477	frontPolys,
478	tData.mDepth + 1,
479	mRootCell,
480	tData.mRays,
481	tData.mPvs,
482	mBox.SurfaceArea(),
483	new BspNodeGeometry());
484
485	BspTraversalData backData(interior->GetBack(),
486	backPolys,
487	tData.mDepth + 1,
488	mRootCell,
489	tData.mRays,
490	tData.mPvs,
491	mBox.SurfaceArea(),
492	new BspNodeGeometry());
493
494	if (!mGenerateViewCells)
495	{
496	ExtractViewCells(frontData,
497	backData,
498	coincident,
499	interior->mPlane);
500	}
501
502	// don't need coincident polygons anymore
503	CLEAR_CONTAINER(coincident);
504
505	mStat.splits += splits;
506
507	// push the children on the stack
508	tStack.push(frontData);
509	tStack.push(backData);
510	}
511
512	// cleanup
513	DEL_PTR(tData.mPolygons);
514	DEL_PTR(tData.mRays);
515	}
516	else
517	{
518	// reached leaf => subdivide current viewcell
519	BspNode *subRoot = Subdivide(tStack, tData);
520	}
521	}
522	}
523
524	int BspTree::AddMeshToPolygons(Mesh *mesh,
525	PolygonContainer &polys,
526	MeshInstance *parent)
527	{
528	FaceContainer::const_iterator fi;
529
530	// copy the face data to polygons
531	for (fi = mesh->mFaces.begin(); fi != mesh->mFaces.end(); ++ fi)
532	{
533	Polygon3 poly = new Polygon3((fi), mesh);
534
535	if (poly->Valid(mEpsilon))
536	{
537	poly->mParent = parent; // set parent intersectable
538	polys.push_back(poly);
539	}
540	else
541	DEL_PTR(poly);
542	}
543	return (int)mesh->mFaces.size();
544	}
545
546	int BspTree::AddToPolygonSoup(const ViewCellContainer &viewCells,
547	PolygonContainer &polys,
548	int maxObjects)
549	{
550	int limit = (maxObjects > 0) ?
551	Min((int)viewCells.size(), maxObjects) : (int)viewCells.size();
552
553	int polysSize = 0;
554
555	for (int i = 0; i < limit; ++ i)
556	{
557	if (viewCells[i]->GetMesh()) // copy the mesh data to polygons
558	{
559	mBox.Include(viewCells[i]->GetBox()); // add to BSP tree aabb
560	polysSize += AddMeshToPolygons(viewCells[i]->GetMesh(), polys, viewCells[i]);
561	}
562	}
563
564	return polysSize;
565	}
566
567	int BspTree::AddToPolygonSoup(const ObjectContainer &objects, PolygonContainer &polys, int maxObjects)
568	{
569	int limit = (maxObjects > 0) ? Min((int)objects.size(), maxObjects) : (int)objects.size();
570
571	for (int i = 0; i < limit; ++i)
572	{
573	Intersectable object = objects[i];//it;
574	Mesh *mesh = NULL;
575
576	switch (object->Type()) // extract the meshes
577	{
578	case Intersectable::MESH_INSTANCE:
579	mesh = dynamic_cast<MeshInstance *>(object)->GetMesh();
580	break;
581	case Intersectable::VIEW_CELL:
582	mesh = dynamic_cast<ViewCell *>(object)->GetMesh();
583	break;
584	// TODO: handle transformed mesh instances
585	default:
586	Debug << "intersectable type not supported" << endl;
587	break;
588	}
589
590	if (mesh) // copy the mesh data to polygons
591	{
592	mBox.Include(object->GetBox()); // add to BSP tree aabb
593	AddMeshToPolygons(mesh, polys, mRootCell);
594	}
595	}
596
597	return (int)polys.size();
598	}
599
600	void BspTree::Construct(const ViewCellContainer &viewCells)
601	{
602	mStat.nodes = 1;
603	mBox.Initialize(); // initialise bsp tree bounding box
604
605	// copy view cell meshes into one big polygon soup
606	PolygonContainer *polys = new PolygonContainer();
607	mStat.polys = AddToPolygonSoup(viewCells, *polys);
608
609	// view cells are given
610	mGenerateViewCells = false;
611	// construct tree from the view cell polygons
612	Construct(polys, new BoundedRayContainer());
613	}
614
615
616	void BspTree::Construct(const ObjectContainer &objects)
617	{
618	mStat.nodes = 1;
619	mBox.Initialize(); // initialise bsp tree bounding box
620
621	PolygonContainer *polys = new PolygonContainer();
622
623	mGenerateViewCells = true;
624	// copy mesh instance polygons into one big polygon soup
625	mStat.polys = AddToPolygonSoup(objects, *polys);
626
627	// construct tree from polygon soup
628	Construct(polys, new BoundedRayContainer());
629	}
630
631	void BspTree::Construct(const RayContainer &sampleRays)
632	{
633	mStat.nodes = 1;
634	mBox.Initialize(); // initialise BSP tree bounding box
635
636	PolygonContainer *polys = new PolygonContainer();
637	BoundedRayContainer *rays = new BoundedRayContainer();
638
639	RayContainer::const_iterator rit, rit_end = sampleRays.end();
640
641	// generate view cells
642	mGenerateViewCells = true;
643
644	long startTime = GetTime();
645
646	Debug << "** Extracting polygons from rays **\n";
647
648	std::map<Face , Polygon3 > facePolyMap;
649
650	//-- extract polygons intersected by the rays
651	for (rit = sampleRays.begin(); rit != rit_end; ++ rit)
652	{
653	Ray ray = rit;
654
655	// get ray-face intersection. Store polygon representing the rays together
656	// with rays intersecting the face.
657	if (!ray->intersections.empty())
658	{
659	MeshInstance obj = dynamic_cast<MeshInstance >(ray->intersections[0].mObject);
660	Face *face = obj->GetMesh()->mFaces[ray->intersections[0].mFace];
661
662	std::map<Face , Polygon3 >::iterator it = facePolyMap.find(face);
663
664	if (it != facePolyMap.end())
665	{
666	//store rays if needed for heuristics
667	if (mSplitPlaneStrategy & BLOCKED_RAYS)
668	(*it).second->mPiercingRays.push_back(ray);
669	}
670	else
671	{ //store rays if needed for heuristics
672	Polygon3 *poly = new Polygon3(face, obj->GetMesh());
673	poly->mParent = obj;
674	polys->push_back(poly);
675
676	if (mSplitPlaneStrategy & BLOCKED_RAYS)
677	poly->mPiercingRays.push_back(ray);
678
679	facePolyMap[face] = poly;
680	}
681	}
682	}
683
684	facePolyMap.clear();
685
686	// compute bounding box
687	Polygon3::IncludeInBox(*polys, mBox);
688
689	//-- store rays
690	for (rit = sampleRays.begin(); rit != rit_end; ++ rit)
691	{
692	Ray ray = rit;
693	ray->SetId(-1); // reset id
694
695	float minT, maxT;
696	if (mBox.GetRaySegment(*ray, minT, maxT))
697	rays->push_back(new BoundedRay(ray, minT, maxT));
698	}
699
700	mStat.polys = (int)polys->size();
701
702	Debug << "** Finished polygon extraction **" << endl;
703	Debug << (int)polys->size() << " polys extracted from " << (int)sampleRays.size() << " rays" << endl;
704	Debug << "extraction time: " << TimeDiff(startTime, GetTime())*1e-3 << "s" << endl;
705
706	Construct(polys, rays);
707	}
708
709	void BspTree::Construct(const ObjectContainer &objects, const RayContainer &sampleRays)
710	{
711	mStat.nodes = 1;
712	mBox.Initialize(); // initialise BSP tree bounding box
713
714	BoundedRayContainer *rays = new BoundedRayContainer();
715	PolygonContainer *polys = new PolygonContainer();
716
717	mGenerateViewCells = true;
718
719	// copy mesh instance polygons into one big polygon soup
720	mStat.polys = AddToPolygonSoup(objects, *polys);
721
722	RayContainer::const_iterator rit, rit_end = sampleRays.end();
723
724	//-- store rays
725	for (rit = sampleRays.begin(); rit != rit_end; ++ rit)
726	{
727	Ray ray = rit;
728	ray->SetId(-1); // reset id
729
730	float minT, maxT;
731	if (mBox.GetRaySegment(*ray, minT, maxT))
732	rays->push_back(new BoundedRay(ray, minT, maxT));
733	}
734
735	Debug << "tree has " << (int)polys->size() << " polys, " << (int)sampleRays.size() << " rays" << endl;
736	Construct(polys, rays);
737	}
738
739	void BspTree::Construct(PolygonContainer polys, BoundedRayContainer rays)
740	{
741	BspTraversalStack tStack;
742
743	mRoot = new BspLeaf();
744
745	// constrruct root node geometry
746	BspNodeGeometry *cell = new BspNodeGeometry();
747	ConstructGeometry(mRoot, *cell);
748
749	BspTraversalData tData(mRoot, polys, 0, mRootCell, rays,
750	ComputePvsSize(*rays), cell->GetArea(), cell);
751
752	tStack.push(tData);
753
754	mStat.Start();
755	cout << "Contructing bsp tree ... ";
756	long startTime = GetTime();
757	while (!tStack.empty())
758	{
759	tData = tStack.top();
760
761	tStack.pop();
762
763	// subdivide leaf node
764	BspNode *r = Subdivide(tStack, tData);
765
766	if (r == mRoot)
767	Debug << "BSP tree construction time spent at root: " << TimeDiff(startTime, GetTime())*1e-3 << " secs" << endl;
768	}
769
770	cout << "finished\n";
771
772	mStat.Stop();
773	}
774
775	bool BspTree::TerminationCriteriaMet(const BspTraversalData &data) const
776	{
777	return
778	(((int)data.mPolygons->size() <= mTermMinPolys) \|\|
779	((int)data.mRays->size() <= mTermMinRays) \|\|
780	(data.mPvs <= mTermMinPvs) \|\|
781	(data.mArea <= mTermMinArea) \|\|
782	(data.mDepth >= mTermMaxDepth) \|\|
783	(data.GetAvgRayContribution() < mTermMaxRayContribution));
784	}
785
786	BspNode *BspTree::Subdivide(BspTraversalStack &tStack, BspTraversalData &tData)
787	{
788	//-- terminate traversal
789	if (TerminationCriteriaMet(tData))
790	{
791	BspLeaf leaf = dynamic_cast<BspLeaf >(tData.mNode);
792
793	BspViewCell *viewCell;
794
795	// generate new view cell for each leaf
796	if (mGenerateViewCells)
797	{
798	viewCell = new BspViewCell();
799	}
800	else
801	{
802	// add view cell to leaf
803	viewCell = dynamic_cast<BspViewCell *>(tData.mViewCell);
804	}
805
806	leaf->SetViewCell(viewCell);
807	viewCell->mLeaves.push_back(leaf);
808
809	//-- add pvs
810	if (viewCell != mRootCell)
811	{
812	int conSamp = 0, sampCon = 0;
813	AddToPvs(leaf, *tData.mRays, conSamp, sampCon);
814
815	mStat.contributingSamples += conSamp;
816	mStat.sampleContributions += sampCon;
817	}
818
819	EvaluateLeafStats(tData);
820
821	//-- clean up
822
823	// discard polygons
824	CLEAR_CONTAINER(*tData.mPolygons);
825	// discard rays
826	CLEAR_CONTAINER(*tData.mRays);
827
828	DEL_PTR(tData.mPolygons);
829	DEL_PTR(tData.mRays);
830	DEL_PTR(tData.mGeometry);
831
832	return leaf;
833	}
834
835	//-- continue subdivision
836	PolygonContainer coincident;
837
838	BspTraversalData tFrontData(NULL, new PolygonContainer(), tData.mDepth + 1, mRootCell,
839	new BoundedRayContainer(), 0, 0, new BspNodeGeometry());
840	BspTraversalData tBackData(NULL, new PolygonContainer(), tData.mDepth + 1, mRootCell,
841	new BoundedRayContainer(), 0, 0, new BspNodeGeometry());
842
843	// create new interior node and two leaf nodes
844	BspInterior *interior =
845	SubdivideNode(tData, tFrontData, tBackData, coincident);
846
847	#ifdef _DEBUG
848	// if (frontPolys->empty() && backPolys->empty() && (coincident.size() > 2))
849	// { for (PolygonContainer::iterator it = coincident.begin(); it != coincident.end(); ++it)
850	// Debug << (it) << " " << (it)->GetArea() << " " << (*it)->mParent << endl ;
851	// Debug << endl;}
852	#endif
853
854	// extract view cells from coincident polygons according to plane normal
855	// only if front or back polygons are empty
856	if (!mGenerateViewCells)
857	{
858	ExtractViewCells(tFrontData,
859	tBackData,
860	coincident,
861	interior->mPlane);
862	}
863
864	// don't need coincident polygons anymory
865	CLEAR_CONTAINER(coincident);
866
867	// push the children on the stack
868	tStack.push(tFrontData);
869	tStack.push(tBackData);
870
871	// cleanup
872	DEL_PTR(tData.mNode);
873
874	DEL_PTR(tData.mPolygons);
875	DEL_PTR(tData.mRays);
876	DEL_PTR(tData.mGeometry);
877
878	return interior;
879	}
880
881	void BspTree::ExtractViewCells(BspTraversalData &frontData,
882	BspTraversalData &backData,
883	const PolygonContainer &coincident,
884	const Plane3 &splitPlane) const
885	{
886	// if not empty, tree is further subdivided => don't have to find view cell
887	bool foundFront = !frontData.mPolygons->empty();
888	bool foundBack = !frontData.mPolygons->empty();
889
890	PolygonContainer::const_iterator it =
891	coincident.begin(), it_end = coincident.end();
892
893	//-- find first view cells in front and back leafs
894	for (; !(foundFront && foundBack) && (it != it_end); ++ it)
895	{
896	if (DotProd((*it)->GetNormal(), splitPlane.mNormal) > 0)
897	{
898	backData.mViewCell = dynamic_cast<ViewCell >((it)->mParent);
899	foundBack = true;
900	}
901	else
902	{
903	frontData.mViewCell = dynamic_cast<ViewCell >((it)->mParent);
904	foundFront = true;
905	}
906	}
907	}
908
909	BspInterior *BspTree::SubdivideNode(BspTraversalData &tData,
910	BspTraversalData &frontData,
911	BspTraversalData &backData,
912	PolygonContainer &coincident)
913	{
914	mStat.nodes += 2;
915
916	BspLeaf leaf = dynamic_cast<BspLeaf >(tData.mNode);
917
918	Debug << "*********************" << endl;
919	long startTime = GetTime();
920
921	// select subdivision plane
922	BspInterior *interior =
923	new BspInterior(SelectPlane(leaf, tData));
924	Debug << "time used for split plane selection: " << TimeDiff(startTime, GetTime())*1e-3 << "s" << endl;
925	#ifdef _DEBUG
926	Debug << interior << endl;
927	#endif
928
929
930	Debug << "number of rays: " << (int)tData.mRays->size() << endl;
931	Debug << "number of polys: " << (int)tData.mPolygons->size() << endl;
932
933	startTime = GetTime();
934
935	// subdivide rays into front and back rays
936	SplitRays(interior->mPlane, tData.mRays, frontData.mRays, *backData.mRays);
937
938	Debug << "time used for rays splitting: " << TimeDiff(startTime, GetTime())*1e-3 << "s" << endl;
939
940	startTime = GetTime();
941	// subdivide polygons with plane
942	mStat.splits += SplitPolygons(interior->GetPlane(),
943	*tData.mPolygons,
944	*frontData.mPolygons,
945	*backData.mPolygons,
946	coincident);
947
948	Debug << "time used for polygon splitting: " << TimeDiff(startTime, GetTime())*1e-3 << "s" << endl;
949
950	// compute pvs
951	frontData.mPvs = ComputePvsSize(*frontData.mRays);
952	backData.mPvs = ComputePvsSize(*backData.mRays);
953
954	// split geometry and compute area
955	if (1)
956	{
957	tData.mGeometry->SplitGeometry(*frontData.mGeometry,
958	*backData.mGeometry,
959	interior->mPlane,
960	mBox,
961	mEpsilon);
962
963
964	frontData.mArea = frontData.mGeometry->GetArea();
965	backData.mArea = backData.mGeometry->GetArea();
966	}
967
968	// compute accumulated ray length
969	//frontData.mAccRayLength = AccumulatedRayLength(*frontData.mRays);
970	//backData.mAccRayLength = AccumulatedRayLength(*backData.mRays);
971
972	//-- create front and back leaf
973
974	BspInterior *parent = leaf->GetParent();
975
976	// replace a link from node's parent
977	if (!leaf->IsRoot())
978	{
979	parent->ReplaceChildLink(leaf, interior);
980	interior->SetParent(parent);
981	}
982	else // new root
983	{
984	mRoot = interior;
985	}
986
987	// and setup child links
988	interior->SetupChildLinks(new BspLeaf(interior), new BspLeaf(interior));
989
990	frontData.mNode = interior->GetFront();
991	backData.mNode = interior->GetBack();
992
993	//DEL_PTR(leaf);
994	return interior;
995	}
996
997	void BspTree::SortSplitCandidates(const PolygonContainer &polys,
998	const int axis,
999	vector<SortableEntry> &splitCandidates) const
1000	{
1001	splitCandidates.clear();
1002
1003	int requestedSize = 2 * (int)polys.size();
1004	// creates a sorted split candidates array
1005	splitCandidates.reserve(requestedSize);
1006
1007	PolygonContainer::const_iterator it, it_end = polys.end();
1008
1009	AxisAlignedBox3 box;
1010
1011	// insert all queries
1012	for(it = polys.begin(); it != it_end; ++ it)
1013	{
1014	box.Initialize();
1015	box.Include((it));
1016
1017	splitCandidates.push_back(SortableEntry(SortableEntry::POLY_MIN, box.Min(axis), *it));
1018	splitCandidates.push_back(SortableEntry(SortableEntry::POLY_MAX, box.Max(axis), *it));
1019	}
1020
1021	stable_sort(splitCandidates.begin(), splitCandidates.end());
1022	}
1023
1024
1025	float BspTree::BestCostRatio(const PolygonContainer &polys,
1026	const AxisAlignedBox3 &box,
1027	const int axis,
1028	float &position,
1029	int &objectsBack,
1030	int &objectsFront) const
1031	{
1032	vector<SortableEntry> splitCandidates;
1033
1034	SortSplitCandidates(polys, axis, splitCandidates);
1035
1036	// go through the lists, count the number of objects left and right
1037	// and evaluate the following cost funcion:
1038	// C = ct_div_ci + (ol + or)/queries
1039
1040	int objectsLeft = 0, objectsRight = (int)polys.size();
1041
1042	float minBox = box.Min(axis);
1043	float maxBox = box.Max(axis);
1044	float boxArea = box.SurfaceArea();
1045
1046	float minBand = minBox + mSplitBorder * (maxBox - minBox);
1047	float maxBand = minBox + (1.0f - mSplitBorder) * (maxBox - minBox);
1048
1049	float minSum = 1e20f;
1050	vector<SortableEntry>::const_iterator ci, ci_end = splitCandidates.end();
1051
1052	for(ci = splitCandidates.begin(); ci != ci_end; ++ ci)
1053	{
1054	switch ((*ci).type)
1055	{
1056	case SortableEntry::POLY_MIN:
1057	++ objectsLeft;
1058	break;
1059	case SortableEntry::POLY_MAX:
1060	-- objectsRight;
1061	break;
1062	default:
1063	break;
1064	}
1065
1066	if ((ci).value > minBand && (ci).value < maxBand)
1067	{
1068	AxisAlignedBox3 lbox = box;
1069	AxisAlignedBox3 rbox = box;
1070	lbox.SetMax(axis, (*ci).value);
1071	rbox.SetMin(axis, (*ci).value);
1072
1073	const float sum = objectsLeft * lbox.SurfaceArea() +
1074	objectsRight * rbox.SurfaceArea();
1075
1076	if (sum < minSum)
1077	{
1078	minSum = sum;
1079	position = (*ci).value;
1080
1081	objectsBack = objectsLeft;
1082	objectsFront = objectsRight;
1083	}
1084	}
1085	}
1086
1087	const float oldCost = (float)polys.size();
1088	const float newCost = mAxisAlignedCtDivCi + minSum / boxArea;
1089	const float ratio = newCost / oldCost;
1090
1091
1092	#if 0
1093	Debug << "====================" << endl;
1094	Debug << "costRatio=" << ratio << " pos=" << position<<" t=" << (position - minBox)/(maxBox - minBox)
1095	<< "\t o=(" << objectsBack << "," << objectsFront << ")" << endl;
1096	#endif
1097	return ratio;
1098	}
1099
1100	bool BspTree::SelectAxisAlignedPlane(Plane3 &plane,
1101	const PolygonContainer &polys) const
1102	{
1103	AxisAlignedBox3 box;
1104	box.Initialize();
1105
1106	// create bounding box of region
1107	Polygon3::IncludeInBox(polys, box);
1108
1109	int objectsBack = 0, objectsFront = 0;
1110	int axis = 0;
1111	float costRatio = MAX_FLOAT;
1112	Vector3 position;
1113
1114	//-- area subdivision
1115	for (int i = 0; i < 3; ++ i)
1116	{
1117	float p = 0;
1118	float r = BestCostRatio(polys, box, i, p, objectsBack, objectsFront);
1119
1120	if (r < costRatio)
1121	{
1122	costRatio = r;
1123	axis = i;
1124	position = p;
1125	}
1126	}
1127
1128	if (costRatio >= mMaxCostRatio)
1129	return false;
1130
1131	Vector3 norm(0,0,0); norm[axis] = 1.0f;
1132	plane = Plane3(norm, position);
1133
1134	return true;
1135	}
1136
1137	Plane3 BspTree::SelectPlane(BspLeaf *leaf, BspTraversalData &data)
1138	{
1139	if (data.mPolygons->empty() && data.mRays->empty())
1140	{
1141	Debug << "Warning: No autopartition polygon candidate available\n";
1142
1143	// return axis aligned split
1144	AxisAlignedBox3 box;
1145	box.Initialize();
1146
1147	// create bounding box of region
1148	Polygon3::IncludeInBox(*data.mPolygons, box);
1149
1150	const int axis = box.Size().DrivingAxis();
1151	const Vector3 position = (box.Min()[axis] + box.Max()[axis])*0.5f;
1152
1153	Vector3 norm(0,0,0); norm[axis] = 1.0f;
1154	return Plane3(norm, position);
1155	}
1156
1157	if ((mSplitPlaneStrategy & AXIS_ALIGNED) &&
1158	((int)data.mPolygons->size() > mTermMinPolysForAxisAligned) &&
1159	((int)data.mRays->size() > mTermMinRaysForAxisAligned) &&
1160	((mTermMinObjectsForAxisAligned < 0) \|\|
1161	(Polygon3::ParentObjectsSize(*data.mPolygons) > mTermMinObjectsForAxisAligned)))
1162	{
1163	Plane3 plane;
1164	if (SelectAxisAlignedPlane(plane, *data.mPolygons))
1165	return plane;
1166	}
1167
1168	// simplest strategy: just take next polygon
1169	if (mSplitPlaneStrategy & RANDOM_POLYGON)
1170	{
1171	if (!data.mPolygons->empty())
1172	{
1173	Polygon3 *nextPoly =
1174	(*data.mPolygons)[(int)RandomValue(0, (Real)((int)data.mPolygons->size() - 1))];
1175	return nextPoly->GetSupportingPlane();
1176	}
1177	else
1178	{
1179	const int candidateIdx = (int)RandomValue(0, (Real)((int)data.mRays->size() - 1));
1180	BoundedRay bRay = (data.mRays)[candidateIdx];
1181
1182	Ray *ray = bRay->mRay;
1183
1184	const Vector3 minPt = ray->Extrap(bRay->mMinT);
1185	const Vector3 maxPt = ray->Extrap(bRay->mMaxT);
1186
1187	const Vector3 pt = (maxPt + minPt) * 0.5;
1188
1189	const Vector3 normal = ray->GetDir();
1190
1191	return Plane3(normal, pt);
1192	}
1193
1194	return Plane3();
1195	}
1196
1197	// use heuristics to find appropriate plane
1198	return SelectPlaneHeuristics(leaf, data);
1199	}
1200
1201
1202	Plane3 BspTree::ChooseCandidatePlane(const BoundedRayContainer &rays) const
1203	{
1204	const int candidateIdx = (int)RandomValue(0, (Real)((int)rays.size() - 1));
1205	BoundedRay *bRay = rays[candidateIdx];
1206	Ray *ray = bRay->mRay;
1207
1208	const Vector3 minPt = ray->Extrap(bRay->mMinT);
1209	const Vector3 maxPt = ray->Extrap(bRay->mMaxT);
1210
1211	const Vector3 pt = (maxPt + minPt) * 0.5;
1212
1213	const Vector3 normal = ray->GetDir();
1214
1215	return Plane3(normal, pt);
1216	}
1217
1218	Plane3 BspTree::ChooseCandidatePlane2(const BoundedRayContainer &rays) const
1219	{
1220	Vector3 pt[3];
1221	int idx[3];
1222	int cmaxT = 0;
1223	int cminT = 0;
1224	bool chooseMin = false;
1225
1226	for (int j = 0; j < 3; j ++)
1227	{
1228	idx[j] = (int)RandomValue(0, Real((int)rays.size() * 2 - 1));
1229
1230	if (idx[j] >= (int)rays.size())
1231	{
1232	idx[j] -= (int)rays.size();
1233	chooseMin = (cminT < 2);
1234	}
1235	else
1236	chooseMin = (cmaxT < 2);
1237
1238	BoundedRay *bRay = rays[idx[j]];
1239	pt[j] = chooseMin ? bRay->mRay->Extrap(bRay->mMinT) :
1240	bRay->mRay->Extrap(bRay->mMaxT);
1241	}
1242
1243	return Plane3(pt[0], pt[1], pt[2]);
1244	}
1245
1246	Plane3 BspTree::ChooseCandidatePlane3(const BoundedRayContainer &rays) const
1247	{
1248	Vector3 pt[3];
1249
1250	int idx1 = (int)RandomValue(0, (Real)((int)rays.size() - 1));
1251	int idx2 = (int)RandomValue(0, (Real)((int)rays.size() - 1));
1252
1253	// check if rays different
1254	if (idx1 == idx2)
1255	idx2 = (idx2 + 1) % (int)rays.size();
1256
1257	const BoundedRay *ray1 = rays[idx1];
1258	const BoundedRay *ray2 = rays[idx2];
1259
1260	// normal vector of the plane parallel to both lines
1261	const Vector3 norm =
1262	Normalize(CrossProd(ray1->mRay->GetDir(), ray2->mRay->GetDir()));
1263
1264	const Vector3 orig1 = ray1->mRay->Extrap(ray1->mMinT);
1265	const Vector3 orig2 = ray2->mRay->Extrap(ray2->mMinT);
1266
1267	// vector from line 1 to line 2
1268	const Vector3 vd = orig1 - orig2;
1269
1270	// project vector on normal to get distance
1271	const float dist = DotProd(vd, norm);
1272
1273	// point on plane lies halfway between the two planes
1274	const Vector3 planePt = orig1 + norm * dist * 0.5;
1275
1276	return Plane3(norm, planePt);
1277	}
1278
1279
1280	Plane3 BspTree::SelectPlaneHeuristics(BspLeaf *leaf, BspTraversalData &data)
1281	{
1282	float lowestCost = MAX_FLOAT;
1283	Plane3 bestPlane;
1284	// intermediate plane
1285	Plane3 plane;
1286
1287	const int limit = Min((int)data.mPolygons->size(), mMaxPolyCandidates);
1288	int maxIdx = (int)data.mPolygons->size();
1289
1290	for (int i = 0; i < limit; ++ i)
1291	{
1292	// assure that no index is taken twice
1293	const int candidateIdx = (int)RandomValue(0, (Real)(-- maxIdx));
1294	//Debug << "current Idx: " << maxIdx << " cand idx " << candidateIdx << endl;
1295
1296	Polygon3 poly = (data.mPolygons)[candidateIdx];
1297
1298	// swap candidate to the end to avoid testing same plane
1299	std::swap((data.mPolygons)[maxIdx], (data.mPolygons)[candidateIdx]);
1300
1301	//Polygon3 poly = (data.mPolygons)[(int)RandomValue(0, (int)polys.size() - 1)];
1302
1303	// evaluate current candidate
1304	const float candidateCost =
1305	SplitPlaneCost(poly->GetSupportingPlane(), data);
1306
1307	if (candidateCost < lowestCost)
1308	{
1309	bestPlane = poly->GetSupportingPlane();
1310	lowestCost = candidateCost;
1311	}
1312	}
1313
1314	//-- choose candidate planes extracted from rays
1315	//-- different methods are available
1316	for (int i = 0; i < mMaxRayCandidates; ++ i)
1317	{
1318	plane = ChooseCandidatePlane3(*data.mRays);
1319	const float candidateCost = SplitPlaneCost(plane, data);
1320
1321	if (candidateCost < lowestCost)
1322	{
1323	bestPlane = plane;
1324	lowestCost = candidateCost;
1325	}
1326	}
1327
1328	#ifdef _DEBUG
1329	Debug << "plane lowest cost: " << lowestCost << endl;
1330	#endif
1331
1332	return bestPlane;
1333	}
1334
1335
1336	float BspTree::SplitPlaneCost(const Plane3 &candidatePlane,
1337	const PolygonContainer &polys) const
1338	{
1339	float val = 0;
1340
1341	float sumBalancedPolys = 0;
1342	float sumSplits = 0;
1343	float sumPolyArea = 0;
1344	float sumBalancedViewCells = 0;
1345	float sumBlockedRays = 0;
1346	float totalBlockedRays = 0;
1347	//float totalArea = 0;
1348	int totalViewCells = 0;
1349
1350	// need three unique ids for each type of view cell
1351	// for balanced view cells criterium
1352	ViewCell::NewMail();
1353	const int backId = ViewCell::sMailId;
1354	ViewCell::NewMail();
1355	const int frontId = ViewCell::sMailId;
1356	ViewCell::NewMail();
1357	const int frontAndBackId = ViewCell::sMailId;
1358
1359	bool useRand;;
1360	int limit;
1361
1362	// choose test polyongs randomly if over threshold
1363	if ((int)polys.size() > mMaxTests)
1364	{
1365	useRand = true;
1366	limit = mMaxTests;
1367	}
1368	else
1369	{
1370	useRand = false;
1371	limit = (int)polys.size();
1372	}
1373
1374	for (int i = 0; i < limit; ++ i)
1375	{
1376	const int testIdx = useRand ? (int)RandomValue(0, (Real)(limit - 1)) : i;
1377
1378	Polygon3 *poly = polys[testIdx];
1379
1380	const int classification =
1381	poly->ClassifyPlane(candidatePlane, mEpsilon);
1382
1383	if (mSplitPlaneStrategy & BALANCED_POLYS)
1384	sumBalancedPolys += sBalancedPolysTable[classification];
1385
1386	if (mSplitPlaneStrategy & LEAST_SPLITS)
1387	sumSplits += sLeastPolySplitsTable[classification];
1388
1389	if (mSplitPlaneStrategy & LARGEST_POLY_AREA)
1390	{
1391	if (classification == Polygon3::COINCIDENT)
1392	sumPolyArea += poly->GetArea();
1393	//totalArea += area;
1394	}
1395
1396	if (mSplitPlaneStrategy & BLOCKED_RAYS)
1397	{
1398	const float blockedRays = (float)poly->mPiercingRays.size();
1399
1400	if (classification == Polygon3::COINCIDENT)
1401	sumBlockedRays += blockedRays;
1402
1403	totalBlockedRays += blockedRays;
1404	}
1405
1406	// assign view cells to back or front according to classificaion
1407	if (mSplitPlaneStrategy & BALANCED_VIEW_CELLS)
1408	{
1409	MeshInstance *viewCell = poly->mParent;
1410
1411	// assure that we only count a view cell
1412	// once for the front and once for the back side of the plane
1413	if (classification == Polygon3::FRONT_SIDE)
1414	{
1415	if ((viewCell->mMailbox != frontId) &&
1416	(viewCell->mMailbox != frontAndBackId))
1417	{
1418	sumBalancedViewCells += 1.0;
1419
1420	if (viewCell->mMailbox != backId)
1421	viewCell->mMailbox = frontId;
1422	else
1423	viewCell->mMailbox = frontAndBackId;
1424
1425	++ totalViewCells;
1426	}
1427	}
1428	else if (classification == Polygon3::BACK_SIDE)
1429	{
1430	if ((viewCell->mMailbox != backId) &&
1431	(viewCell->mMailbox != frontAndBackId))
1432	{
1433	sumBalancedViewCells -= 1.0;
1434
1435	if (viewCell->mMailbox != frontId)
1436	viewCell->mMailbox = backId;
1437	else
1438	viewCell->mMailbox = frontAndBackId;
1439
1440	++ totalViewCells;
1441	}
1442	}
1443	}
1444	}
1445
1446	const float polysSize = (float)polys.size() + Limits::Small;
1447
1448	// all values should be approx. between 0 and 1 so they can be combined
1449	// and scaled with the factors according to their importance
1450	if (mSplitPlaneStrategy & BALANCED_POLYS)
1451	val += mBalancedPolysFactor * fabs(sumBalancedPolys) / polysSize;
1452
1453	if (mSplitPlaneStrategy & LEAST_SPLITS)
1454	val += mLeastSplitsFactor * sumSplits / polysSize;
1455
1456	if (mSplitPlaneStrategy & LARGEST_POLY_AREA)
1457	// HACK: polys.size should be total area so scaling is between 0 and 1
1458	val += mLargestPolyAreaFactor * (float)polys.size() / sumPolyArea;
1459
1460	if (mSplitPlaneStrategy & BLOCKED_RAYS)
1461	if (totalBlockedRays != 0)
1462	val += mBlockedRaysFactor * (totalBlockedRays - sumBlockedRays) / totalBlockedRays;
1463
1464	if (mSplitPlaneStrategy & BALANCED_VIEW_CELLS)
1465	val += mBalancedViewCellsFactor * fabs(sumBalancedViewCells) /
1466	((float)totalViewCells + Limits::Small);
1467
1468	return val;
1469	}
1470
1471
1472	inline void BspTree::GenerateUniqueIdsForPvs()
1473	{
1474	Intersectable::NewMail(); sBackId = ViewCell::sMailId;
1475	Intersectable::NewMail(); sFrontId = ViewCell::sMailId;
1476	Intersectable::NewMail(); sFrontAndBackId = ViewCell::sMailId;
1477	}
1478
1479	float BspTree::SplitPlaneCost(const Plane3 &candidatePlane,
1480	const BoundedRayContainer &rays,
1481	const int pvs,
1482	const float area,
1483	const BspNodeGeometry &cell) const
1484	{
1485	float val = 0;
1486
1487	float sumBalancedRays = 0;
1488	float sumRaySplits = 0;
1489
1490	int frontPvs = 0;
1491	int backPvs = 0;
1492
1493	// probability that view point lies in child
1494	float pOverall = 0;
1495	float pFront = 0;
1496	float pBack = 0;
1497
1498	const bool pvsUseLen = false;
1499
1500	if (mSplitPlaneStrategy & PVS)
1501	{
1502	// create unique ids for pvs heuristics
1503	GenerateUniqueIdsForPvs();
1504
1505	if (mPvsUseArea) // use front and back cell areas to approximate volume
1506	{
1507	// construct child geometry with regard to the candidate split plane
1508	BspNodeGeometry frontCell;
1509	BspNodeGeometry backCell;
1510
1511	cell.SplitGeometry(frontCell,
1512	backCell,
1513	candidatePlane,
1514	mBox,
1515	mEpsilon);
1516
1517	pFront = frontCell.GetArea();
1518	pBack = backCell.GetArea();
1519
1520	pOverall = area;
1521	}
1522	}
1523
1524	bool useRand;;
1525	int limit;
1526
1527	// choose test polyongs randomly if over threshold
1528	if ((int)rays.size() > mMaxTests)
1529	{
1530	useRand = true;
1531	limit = mMaxTests;
1532	}
1533	else
1534	{
1535	useRand = false;
1536	limit = (int)rays.size();
1537	}
1538
1539	for (int i = 0; i < limit; ++ i)
1540	{
1541	const int testIdx = useRand ? (int)RandomValue(0, (Real)(limit - 1)) : i;
1542
1543	BoundedRay *bRay = rays[testIdx];
1544
1545	Ray *ray = bRay->mRay;
1546	const float minT = bRay->mMinT;
1547	const float maxT = bRay->mMaxT;
1548
1549	Vector3 entP, extP;
1550
1551	const int cf =
1552	ray->ClassifyPlane(candidatePlane, minT, maxT, entP, extP);
1553
1554	if (mSplitPlaneStrategy & LEAST_RAY_SPLITS)
1555	{
1556	sumBalancedRays += sBalancedRaysTable[cf];
1557	}
1558
1559	if (mSplitPlaneStrategy & BALANCED_RAYS)
1560	{
1561	sumRaySplits += sLeastRaySplitsTable[cf];
1562	}
1563
1564	if (mSplitPlaneStrategy & PVS)
1565	{
1566	// in case the ray intersects an object
1567	// assure that we only count the object
1568	// once for the front and once for the back side of the plane
1569
1570	// add the termination object
1571	if (!ray->intersections.empty())
1572	AddObjToPvs(ray->intersections[0].mObject, cf, frontPvs, backPvs);
1573
1574	// add the source object
1575	AddObjToPvs(ray->sourceObject.mObject, cf, frontPvs, backPvs);
1576
1577	if (mPvsUseArea)
1578	{
1579	float len = 1;
1580
1581	if (pvsUseLen)
1582	len = SqrDistance(entP, extP);
1583
1584	// use length of rays to approximate volume
1585	if (Ray::BACK && Ray::COINCIDENT)
1586	pBack += len;
1587	if (Ray::FRONT && Ray::COINCIDENT)
1588	pFront += len;
1589	if (Ray::FRONT_BACK \|\| Ray::BACK_FRONT)
1590	{
1591	if (pvsUseLen)
1592	{
1593	const Vector3 extp = ray->Extrap(maxT);
1594	const float t = candidatePlane.FindT(ray->GetLoc(), extp);
1595
1596	const float newT = t * maxT;
1597	const float newLen = SqrDistance(ray->Extrap(newT), extp);
1598
1599	if (Ray::FRONT_BACK)
1600	{
1601	pFront += len - newLen;
1602	pBack += newLen;
1603	}
1604	else
1605	{
1606	pBack += len - newLen;
1607	pFront += newLen;
1608	}
1609	}
1610	else
1611	{
1612	++ pFront;
1613	++ pBack;
1614	}
1615	}
1616	}
1617	}
1618	}
1619
1620	const float raysSize = (float)rays.size() + Limits::Small;
1621
1622	if (mSplitPlaneStrategy & LEAST_RAY_SPLITS)
1623	val += mLeastRaySplitsFactor * sumRaySplits / raysSize;
1624
1625	if (mSplitPlaneStrategy & BALANCED_RAYS)
1626	val += mBalancedRaysFactor * fabs(sumBalancedRays) / raysSize;
1627
1628	const float denom = pOverall * (float)pvs * 2.0f + Limits::Small;
1629
1630	if (mSplitPlaneStrategy & PVS)
1631	{
1632	val += mPvsFactor * (frontPvs * pFront + (backPvs * pBack)) / denom;
1633
1634	// give penalty to unbalanced split
1635	if (0)
1636	if (((pFront * 0.2 + Limits::Small) > pBack) \|\|
1637	(pFront < (pBack * 0.2 + Limits::Small)))
1638	val += 0.5;
1639	}
1640
1641
1642	#ifdef _DEBUG
1643	Debug << "totalpvs: " << pvs << " ptotal: " << pOverall
1644	<< " frontpvs: " << frontPvs << " pFront: " << pFront
1645	<< " backpvs: " << backPvs << " pBack: " << pBack << endl << endl;
1646	#endif
1647
1648	return val;
1649	}
1650
1651	void BspTree::AddObjToPvs(Intersectable *obj,
1652	const int cf,
1653	int &frontPvs,
1654	int &backPvs) const
1655	{
1656	if (!obj)
1657	return;
1658	// TODO: does this really belong to no pvs?
1659	//if (cf == Ray::COINCIDENT) return;
1660
1661	// object belongs to both PVS
1662	const bool bothSides = (cf == Ray::FRONT_BACK) \|\|
1663	(cf == Ray::BACK_FRONT) \|\|
1664	(cf == Ray::COINCIDENT);
1665
1666	if ((cf == Ray::FRONT) \|\| bothSides)
1667	{
1668	if ((obj->mMailbox != sFrontId) &&
1669	(obj->mMailbox != sFrontAndBackId))
1670	{
1671	++ frontPvs;
1672
1673	if (obj->mMailbox == sBackId)
1674	obj->mMailbox = sFrontAndBackId;
1675	else
1676	obj->mMailbox = sFrontId;
1677	}
1678	}
1679
1680	if ((cf == Ray::BACK) \|\| bothSides)
1681	{
1682	if ((obj->mMailbox != sBackId) &&
1683	(obj->mMailbox != sFrontAndBackId))
1684	{
1685	++ backPvs;
1686
1687	if (obj->mMailbox == sFrontId)
1688	obj->mMailbox = sFrontAndBackId;
1689	else
1690	obj->mMailbox = sBackId;
1691	}
1692	}
1693	}
1694
1695	float BspTree::SplitPlaneCost(const Plane3 &candidatePlane,
1696	BspTraversalData &data) const
1697	{
1698	float val = 0;
1699
1700	if (mSplitPlaneStrategy & VERTICAL_AXIS)
1701	{
1702	Vector3 tinyAxis(0,0,0); tinyAxis[mBox.Size().TinyAxis()] = 1.0f;
1703	// we put a penalty on the dot product between the "tiny" vertical axis
1704	// and the split plane axis
1705	val += mVerticalSplitsFactor *
1706	fabs(DotProd(candidatePlane.mNormal, tinyAxis));
1707	}
1708
1709	// the following criteria loop over all polygons to find the cost value
1710	if ((mSplitPlaneStrategy & BALANCED_POLYS) \|\|
1711	(mSplitPlaneStrategy & LEAST_SPLITS) \|\|
1712	(mSplitPlaneStrategy & LARGEST_POLY_AREA) \|\|
1713	(mSplitPlaneStrategy & BALANCED_VIEW_CELLS) \|\|
1714	(mSplitPlaneStrategy & BLOCKED_RAYS))
1715	{
1716	val += SplitPlaneCost(candidatePlane, *data.mPolygons);
1717	}
1718
1719	// the following criteria loop over all rays to find the cost value
1720	if ((mSplitPlaneStrategy & BALANCED_RAYS) \|\|
1721	(mSplitPlaneStrategy & LEAST_RAY_SPLITS) \|\|
1722	(mSplitPlaneStrategy & PVS))
1723	{
1724	val += SplitPlaneCost(candidatePlane, *data.mRays, data.mPvs,
1725	data.mArea, *data.mGeometry);
1726	}
1727
1728	// return linear combination of the sums
1729	return val;
1730	}
1731
1732	void BspTree::CollectLeaves(vector<BspLeaf *> &leaves) const
1733	{
1734	stack<BspNode *> nodeStack;
1735	nodeStack.push(mRoot);
1736
1737	while (!nodeStack.empty())
1738	{
1739	BspNode *node = nodeStack.top();
1740
1741	nodeStack.pop();
1742
1743	if (node->IsLeaf())
1744	{
1745	BspLeaf leaf = (BspLeaf )node;
1746	leaves.push_back(leaf);
1747	}
1748	else
1749	{
1750	BspInterior interior = dynamic_cast<BspInterior >(node);
1751
1752	nodeStack.push(interior->GetBack());
1753	nodeStack.push(interior->GetFront());
1754	}
1755	}
1756	}
1757
1758	AxisAlignedBox3 BspTree::GetBoundingBox() const
1759	{
1760	return mBox;
1761	}
1762
1763	BspNode *BspTree::GetRoot() const
1764	{
1765	return mRoot;
1766	}
1767
1768	void BspTree::EvaluateLeafStats(const BspTraversalData &data)
1769	{
1770	// the node became a leaf -> evaluate stats for leafs
1771	BspLeaf leaf = dynamic_cast<BspLeaf >(data.mNode);
1772
1773	// store maximal and minimal depth
1774	if (data.mDepth > mStat.maxDepth)
1775	mStat.maxDepth = data.mDepth;
1776
1777	if (data.mDepth < mStat.minDepth)
1778	mStat.minDepth = data.mDepth;
1779
1780	// accumulate depth to compute average depth
1781	mStat.accumDepth += data.mDepth;
1782
1783
1784	if (data.mDepth >= mTermMaxDepth)
1785	++ mStat.maxDepthNodes;
1786
1787	if (data.mPvs < mTermMinPvs)
1788	++ mStat.minPvsNodes;
1789
1790	if ((int)data.mRays->size() < mTermMinRays)
1791	++ mStat.minRaysNodes;
1792
1793	if (data.GetAvgRayContribution() > mTermMaxRayContribution)
1794	++ mStat.maxRayContribNodes;
1795
1796	if (data.mGeometry->GetArea() <= mTermMinArea)
1797	++ mStat.minAreaNodes;
1798
1799	#ifdef _DEBUG
1800	Debug << "BSP stats: "
1801	<< "Depth: " << data.mDepth << " (max: " << mTermMaxDepth << "), "
1802	<< "PVS: " << data.mPvs << " (min: " << mTermMinPvs << "), "
1803	<< "Area: " << data.mArea << " (min: " << mTermMinArea << "), "
1804	<< "#polygons: " << (int)data.mPolygons->size() << " (max: " << mTermMinPolys << "), "
1805	<< "#rays: " << (int)data.mRays->size() << " (max: " << mTermMinRays << "), "
1806	<< "#pvs: " << leaf->GetViewCell()->GetPvs().GetSize() << "=, "
1807	<< "#avg ray contrib (pvs): " << (float)data.mPvs / (float)data.mRays->size() << endl;
1808	#endif
1809	}
1810
1811	int
1812	BspTree::_CastRay(Ray &ray)
1813	{
1814	int hits = 0;
1815
1816	stack<BspRayTraversalData> tStack;
1817
1818	float maxt, mint;
1819
1820	if (!mBox.GetRaySegment(ray, mint, maxt))
1821	return 0;
1822
1823	Intersectable::NewMail();
1824
1825	Vector3 entp = ray.Extrap(mint);
1826	Vector3 extp = ray.Extrap(maxt);
1827
1828	BspNode *node = mRoot;
1829	BspNode *farChild = NULL;
1830
1831	while (1)
1832	{
1833	if (!node->IsLeaf())
1834	{
1835	BspInterior in = dynamic_cast<BspInterior >(node);
1836
1837	Plane3 splitPlane = in->GetPlane();
1838	const int entSide = splitPlane.Side(entp);
1839	const int extSide = splitPlane.Side(extp);
1840
1841	if (entSide < 0)
1842	{
1843	node = in->GetBack();
1844
1845	if(extSide <= 0) // plane does not split ray => no far child
1846	continue;
1847
1848	farChild = in->GetFront(); // plane splits ray
1849
1850	} else if (entSide > 0)
1851	{
1852	node = in->GetFront();
1853
1854	if (extSide >= 0) // plane does not split ray => no far child
1855	continue;
1856
1857	farChild = in->GetBack(); // plane splits ray
1858	}
1859	else // ray and plane are coincident
1860	{
1861	// WHAT TO DO IN THIS CASE ?
1862	//break;
1863	node = in->GetFront();
1864	continue;
1865	}
1866
1867	// push data for far child
1868	tStack.push(BspRayTraversalData(farChild, extp, maxt));
1869
1870	// find intersection of ray segment with plane
1871	float t;
1872	extp = splitPlane.FindIntersection(ray.GetLoc(), extp, &t);
1873	maxt *= t;
1874
1875	} else // reached leaf => intersection with view cell
1876	{
1877	BspLeaf leaf = dynamic_cast<BspLeaf >(node);
1878
1879	if (!leaf->mViewCell->Mailed())
1880	{
1881	// ray.bspIntersections.push_back(Ray::BspIntersection(maxt, leaf));
1882	leaf->mViewCell->Mail();
1883	++ hits;
1884	}
1885
1886	//-- fetch the next far child from the stack
1887	if (tStack.empty())
1888	break;
1889
1890	entp = extp;
1891	mint = maxt; // NOTE: need this?
1892
1893	if (ray.GetType() == Ray::LINE_SEGMENT && mint > 1.0f)
1894	break;
1895
1896	BspRayTraversalData &s = tStack.top();
1897
1898	node = s.mNode;
1899	extp = s.mExitPoint;
1900	maxt = s.mMaxT;
1901
1902	tStack.pop();
1903	}
1904	}
1905
1906	return hits;
1907	}
1908
1909
1910	int BspTree::CastLineSegment(const Vector3 &origin,
1911	const Vector3 &termination,
1912	vector<ViewCell *> &viewcells)
1913	{
1914	int hits = 0;
1915	stack<BspRayTraversalData> tStack;
1916
1917	float mint = 0.0f, maxt = 1.0f;
1918
1919	Intersectable::NewMail();
1920
1921	Vector3 entp = origin;
1922	Vector3 extp = termination;
1923
1924	BspNode *node = mRoot;
1925	BspNode *farChild = NULL;
1926
1927	while (1)
1928	{
1929	if (!node->IsLeaf())
1930	{
1931	BspInterior in = dynamic_cast<BspInterior >(node);
1932
1933	Plane3 splitPlane = in->GetPlane();
1934
1935	const int entSide = splitPlane.Side(entp);
1936	const int extSide = splitPlane.Side(extp);
1937
1938	if (entSide < 0)
1939	{
1940	node = in->GetBack();
1941
1942	if(extSide <= 0) // plane does not split ray => no far child
1943	continue;
1944
1945	farChild = in->GetFront(); // plane splits ray
1946
1947	}
1948	else if (entSide > 0)
1949	{
1950	node = in->GetFront();
1951
1952	if (extSide >= 0) // plane does not split ray => no far child
1953	continue;
1954
1955	farChild = in->GetBack(); // plane splits ray
1956	}
1957	else // ray and plane are coincident
1958	{
1959	// WHAT TO DO IN THIS CASE ?
1960	//break;
1961	node = in->GetFront();
1962	continue;
1963	}
1964
1965	// push data for far child
1966	tStack.push(BspRayTraversalData(farChild, extp, maxt));
1967
1968	// find intersection of ray segment with plane
1969	float t;
1970	extp = splitPlane.FindIntersection(origin, extp, &t);
1971	maxt *= t;
1972	}
1973	else
1974	{
1975	// reached leaf => intersection with view cell
1976	BspLeaf leaf = dynamic_cast<BspLeaf >(node);
1977
1978	if (!leaf->mViewCell->Mailed())
1979	{
1980	viewcells.push_back(leaf->mViewCell);
1981	leaf->mViewCell->Mail();
1982	hits++;
1983	}
1984
1985	//-- fetch the next far child from the stack
1986	if (tStack.empty())
1987	break;
1988
1989	entp = extp;
1990	mint = maxt; // NOTE: need this?
1991
1992	BspRayTraversalData &s = tStack.top();
1993
1994	node = s.mNode;
1995	extp = s.mExitPoint;
1996	maxt = s.mMaxT;
1997
1998	tStack.pop();
1999	}
2000	}
2001	return hits;
2002	}
2003
2004	bool BspTree::Export(const string filename)
2005	{
2006	Exporter *exporter = Exporter::GetExporter(filename);
2007
2008	if (exporter)
2009	{
2010	exporter->ExportBspTree(*this);
2011	return true;
2012	}
2013
2014	return false;
2015	}
2016
2017	void BspTree::CollectViewCells(ViewCellContainer &viewCells) const
2018	{
2019	stack<BspNode *> nodeStack;
2020	nodeStack.push(mRoot);
2021
2022	ViewCell::NewMail();
2023
2024	while (!nodeStack.empty())
2025	{
2026	BspNode *node = nodeStack.top();
2027	nodeStack.pop();
2028
2029	if (node->IsLeaf())
2030	{
2031	ViewCell viewCell = dynamic_cast<BspLeaf >(node)->mViewCell;
2032
2033	if (!viewCell->Mailed())
2034	{
2035	viewCell->Mail();
2036	viewCells.push_back(viewCell);
2037	}
2038	}
2039	else
2040	{
2041	BspInterior interior = dynamic_cast<BspInterior >(node);
2042
2043	nodeStack.push(interior->GetFront());
2044	nodeStack.push(interior->GetBack());
2045	}
2046	}
2047	}
2048
2049
2050	BspTreeStatistics &BspTree::GetStat()
2051	{
2052	return mStat;
2053	}
2054
2055
2056	float BspTree::AccumulatedRayLength(BoundedRayContainer &rays) const
2057	{
2058	float len = 0;
2059
2060	BoundedRayContainer::const_iterator it, it_end = rays.end();
2061
2062	for (it = rays.begin(); it != it_end; ++ it)
2063	{
2064	len += SqrDistance((it)->mRay->Extrap((it)->mMinT),
2065	(it)->mRay->Extrap((it)->mMaxT));
2066	}
2067
2068	return len;
2069	}
2070
2071
2072	int BspTree::SplitRays(const Plane3 &plane,
2073	BoundedRayContainer &rays,
2074	BoundedRayContainer &frontRays,
2075	BoundedRayContainer &backRays)
2076	{
2077	int splits = 0;
2078
2079	while (!rays.empty())
2080	{
2081	BoundedRay *bRay = rays.back();
2082	Ray *ray = bRay->mRay;
2083	float minT = bRay->mMinT;
2084	float maxT = bRay->mMaxT;
2085
2086	rays.pop_back();
2087
2088	Vector3 entP, extP;
2089
2090	const int cf =
2091	ray->ClassifyPlane(plane, minT, maxT, entP, extP);
2092
2093	// set id to ray classification
2094	ray->SetId(cf);
2095
2096	switch (cf)
2097	{
2098	case Ray::COINCIDENT: // TODO: should really discard ray?
2099	frontRays.push_back(bRay);
2100	//DEL_PTR(bRay);
2101	break;
2102	case Ray::BACK:
2103	backRays.push_back(bRay);
2104	break;
2105	case Ray::FRONT:
2106	frontRays.push_back(bRay);
2107	break;
2108	case Ray::FRONT_BACK:
2109	{
2110	// find intersection of ray segment with plane
2111	const float t = plane.FindT(ray->GetLoc(), extP);
2112
2113	const float newT = t * maxT;
2114
2115	frontRays.push_back(new BoundedRay(ray, minT, newT));
2116	backRays.push_back(new BoundedRay(ray, newT, maxT));
2117
2118	DEL_PTR(bRay);
2119	}
2120	break;
2121	case Ray::BACK_FRONT:
2122	{
2123	// find intersection of ray segment with plane
2124	const float t = plane.FindT(ray->GetLoc(), extP);
2125	const float newT = t * bRay->mMaxT;
2126
2127	backRays.push_back(new BoundedRay(ray, minT, newT));
2128	frontRays.push_back(new BoundedRay(ray, newT, maxT));
2129
2130	DEL_PTR(bRay);
2131
2132	++ splits;
2133	}
2134	break;
2135	default:
2136	Debug << "Should not come here 4" << endl;
2137	break;
2138	}
2139	}
2140
2141	return splits;
2142	}
2143
2144	void BspTree::ExtractHalfSpaces(BspNode *n, vector<Plane3> &halfSpaces) const
2145	{
2146	BspNode *lastNode;
2147	do
2148	{
2149	lastNode = n;
2150
2151	// want to get planes defining geometry of this node => don't take
2152	// split plane of node itself
2153	n = n->GetParent();
2154
2155	if (n)
2156	{
2157	BspInterior interior = dynamic_cast<BspInterior >(n);
2158	Plane3 halfSpace = dynamic_cast<BspInterior *>(interior)->GetPlane();
2159
2160	if (interior->GetFront() != lastNode)
2161	halfSpace.ReverseOrientation();
2162
2163	halfSpaces.push_back(halfSpace);
2164	}
2165	}
2166	while (n);
2167	}
2168
2169	void BspTree::ConstructGeometry(BspNode *n, BspNodeGeometry &cell) const
2170	{
2171	PolygonContainer polys;
2172	ConstructGeometry(n, polys);
2173	cell.mPolys = polys;
2174	}
2175
2176	void BspTree::ConstructGeometry(BspViewCell *vc, PolygonContainer &cell) const
2177	{
2178	vector<BspLeaf *> leaves = vc->mLeaves;
2179
2180	vector<BspLeaf *>::const_iterator it, it_end = leaves.end();
2181
2182	for (it = leaves.begin(); it != it_end; ++ it)
2183	ConstructGeometry(*it, cell);
2184	}
2185
2186
2187	void BspTree::ConstructGeometry(BspNode *n, PolygonContainer &cell) const
2188	{
2189	vector<Plane3> halfSpaces;
2190	ExtractHalfSpaces(n, halfSpaces);
2191
2192	PolygonContainer candidates;
2193
2194	// bounded planes are added to the polygons (reverse polygons
2195	// as they have to be outfacing
2196	for (int i = 0; i < (int)halfSpaces.size(); ++ i)
2197	{
2198	Polygon3 *p = GetBoundingBox().CrossSection(halfSpaces[i]);
2199
2200	if (p->Valid(mEpsilon))
2201	{
2202	candidates.push_back(p->CreateReversePolygon());
2203	DEL_PTR(p);
2204	}
2205	}
2206
2207	// add faces of bounding box (also could be faces of the cell)
2208	for (int i = 0; i < 6; ++ i)
2209	{
2210	VertexContainer vertices;
2211
2212	for (int j = 0; j < 4; ++ j)
2213	vertices.push_back(mBox.GetFace(i).mVertices[j]);
2214
2215	candidates.push_back(new Polygon3(vertices));
2216	}
2217
2218	for (int i = 0; i < (int)candidates.size(); ++ i)
2219	{
2220	// polygon is split by all other planes
2221	for (int j = 0; (j < (int)halfSpaces.size()) && candidates[i]; ++ j)
2222	{
2223	if (i == j) // polygon and plane are coincident
2224	continue;
2225
2226	VertexContainer splitPts;
2227	Polygon3 frontPoly, backPoly;
2228
2229	const int cf = candidates[i]->
2230	ClassifyPlane(halfSpaces[j], mEpsilon);
2231
2232	switch (cf)
2233	{
2234	case Polygon3::SPLIT:
2235	frontPoly = new Polygon3();
2236	backPoly = new Polygon3();
2237
2238	candidates[i]->Split(halfSpaces[j],
2239	*frontPoly,
2240	*backPoly,
2241	mEpsilon);
2242
2243	DEL_PTR(candidates[i]);
2244
2245	if (frontPoly->Valid(mEpsilon))
2246	candidates[i] = frontPoly;
2247	else
2248	DEL_PTR(frontPoly);
2249
2250	DEL_PTR(backPoly);
2251	break;
2252	case Polygon3::BACK_SIDE:
2253	DEL_PTR(candidates[i]);
2254	break;
2255	// just take polygon as it is
2256	case Polygon3::FRONT_SIDE:
2257	case Polygon3::COINCIDENT:
2258	default:
2259	break;
2260	}
2261	}
2262
2263	if (candidates[i])
2264	cell.push_back(candidates[i]);
2265	}
2266	}
2267
2268
2269	int BspTree::FindNeighbors(BspNode n, vector<BspLeaf > &neighbors,
2270	const bool onlyUnmailed) const
2271	{
2272	PolygonContainer cell;
2273
2274	ConstructGeometry(n, cell);
2275
2276	stack<BspNode *> nodeStack;
2277	nodeStack.push(mRoot);
2278
2279	// planes needed to verify that we found neighbor leaf.
2280	vector<Plane3> halfSpaces;
2281	ExtractHalfSpaces(n, halfSpaces);
2282
2283	while (!nodeStack.empty())
2284	{
2285	BspNode *node = nodeStack.top();
2286	nodeStack.pop();
2287
2288	if (node->IsLeaf())
2289	{
2290	if (node != n && (!onlyUnmailed \|\| !node->Mailed()))
2291	{
2292	// test all planes of current node if candidate really
2293	// is neighbour
2294	PolygonContainer neighborCandidate;
2295	ConstructGeometry(node, neighborCandidate);
2296
2297	bool isAdjacent = true;
2298	for (int i = 0; (i < halfSpaces.size()) && isAdjacent; ++ i)
2299	{
2300	const int cf =
2301	Polygon3::ClassifyPlane(neighborCandidate,
2302	halfSpaces[i],
2303	mEpsilon);
2304
2305	if (cf == Polygon3::BACK_SIDE)
2306	isAdjacent = false;
2307	}
2308
2309	if (isAdjacent)
2310	neighbors.push_back(dynamic_cast<BspLeaf *>(node));
2311
2312	CLEAR_CONTAINER(neighborCandidate);
2313	}
2314	}
2315	else
2316	{
2317	BspInterior interior = dynamic_cast<BspInterior >(node);
2318
2319	const int cf = Polygon3::ClassifyPlane(cell,
2320	interior->mPlane,
2321	mEpsilon);
2322
2323	if (cf == Polygon3::FRONT_SIDE)
2324	nodeStack.push(interior->GetFront());
2325	else
2326	if (cf == Polygon3::BACK_SIDE)
2327	nodeStack.push(interior->GetBack());
2328	else
2329	{
2330	// random decision
2331	nodeStack.push(interior->GetBack());
2332	nodeStack.push(interior->GetFront());
2333	}
2334	}
2335	}
2336
2337	CLEAR_CONTAINER(cell);
2338	return (int)neighbors.size();
2339	}
2340
2341	BspLeaf *BspTree::GetRandomLeaf(const Plane3 &halfspace)
2342	{
2343	stack<BspNode *> nodeStack;
2344	nodeStack.push(mRoot);
2345
2346	int mask = rand();
2347
2348	while (!nodeStack.empty())
2349	{
2350	BspNode *node = nodeStack.top();
2351	nodeStack.pop();
2352
2353	if (node->IsLeaf())
2354	{
2355	return dynamic_cast<BspLeaf *>(node);
2356	}
2357	else
2358	{
2359	BspInterior interior = dynamic_cast<BspInterior >(node);
2360
2361	BspNode *next;
2362
2363	PolygonContainer cell;
2364
2365	// todo: not very efficient: constructs full cell everytime
2366	ConstructGeometry(interior, cell);
2367
2368	const int cf = Polygon3::ClassifyPlane(cell,
2369	halfspace,
2370	mEpsilon);
2371
2372	if (cf == Polygon3::BACK_SIDE)
2373	next = interior->GetFront();
2374	else
2375	if (cf == Polygon3::FRONT_SIDE)
2376	next = interior->GetFront();
2377	else
2378	{
2379	// random decision
2380	if (mask & 1)
2381	next = interior->GetBack();
2382	else
2383	next = interior->GetFront();
2384	mask = mask >> 1;
2385	}
2386
2387	nodeStack.push(next);
2388	}
2389	}
2390
2391	return NULL;
2392	}
2393
2394	BspLeaf *BspTree::GetRandomLeaf(const bool onlyUnmailed)
2395	{
2396	stack<BspNode *> nodeStack;
2397
2398	nodeStack.push(mRoot);
2399
2400	int mask = rand();
2401
2402	while (!nodeStack.empty())
2403	{
2404	BspNode *node = nodeStack.top();
2405	nodeStack.pop();
2406
2407	if (node->IsLeaf())
2408	{
2409	if ( (!onlyUnmailed \|\| !node->Mailed()) )
2410	return dynamic_cast<BspLeaf *>(node);
2411	}
2412	else
2413	{
2414	BspInterior interior = dynamic_cast<BspInterior >(node);
2415
2416	// random decision
2417	if (mask & 1)
2418	nodeStack.push(interior->GetBack());
2419	else
2420	nodeStack.push(interior->GetFront());
2421
2422	mask = mask >> 1;
2423	}
2424	}
2425
2426	return NULL;
2427	}
2428
2429	void BspTree::AddToPvs(BspLeaf *leaf,
2430	const BoundedRayContainer &rays,
2431	int &sampleContributions,
2432	int &contributingSamples)
2433	{
2434	sampleContributions = 0;
2435	contributingSamples = 0;
2436
2437	BoundedRayContainer::const_iterator it, it_end = rays.end();
2438
2439	ViewCell *vc = leaf->GetViewCell();
2440
2441	// add contributions from samples to the PVS
2442	for (it = rays.begin(); it != it_end; ++ it)
2443	{
2444	int contribution = 0;
2445	Ray ray = (it)->mRay;
2446	float relContribution;
2447	if (!ray->intersections.empty())
2448	contribution += vc->GetPvs().AddSample(ray->intersections[0].mObject, relContribution);
2449
2450	if (ray->sourceObject.mObject)
2451	contribution += vc->GetPvs().AddSample(ray->sourceObject.mObject, relContribution);
2452
2453	if (contribution)
2454	{
2455	sampleContributions += contribution;
2456	++ contributingSamples;
2457	}
2458
2459	//if (ray->mFlags & Ray::STORE_BSP_INTERSECTIONS)
2460	// ray->bspIntersections.push_back(Ray::BspIntersection((*it)->mMinT, this));
2461	}
2462	}
2463
2464	int BspTree::ComputePvsSize(const BoundedRayContainer &rays) const
2465	{
2466	int pvsSize = 0;
2467
2468	BoundedRayContainer::const_iterator rit, rit_end = rays.end();
2469
2470	Intersectable::NewMail();
2471
2472	for (rit = rays.begin(); rit != rays.end(); ++ rit)
2473	{
2474	Ray ray = (rit)->mRay;
2475
2476	if (!ray->intersections.empty())
2477	{
2478	if (!ray->intersections[0].mObject->Mailed())
2479	{
2480	ray->intersections[0].mObject->Mail();
2481	++ pvsSize;
2482	}
2483	}
2484	if (ray->sourceObject.mObject)
2485	{
2486	if (!ray->sourceObject.mObject->Mailed())
2487	{
2488	ray->sourceObject.mObject->Mail();
2489	++ pvsSize;
2490	}
2491	}
2492	}
2493
2494	return pvsSize;
2495	}
2496
2497	float BspTree::GetEpsilon() const
2498	{
2499	return mEpsilon;
2500	}
2501
2502
2503	/*************************************************************/
2504	/* BspNodeGeometry Implementation */
2505	/*************************************************************/
2506
2507	BspNodeGeometry::~BspNodeGeometry()
2508	{
2509	CLEAR_CONTAINER(mPolys);
2510	}
2511
2512	float BspNodeGeometry::GetArea() const
2513	{
2514	return Polygon3::GetArea(mPolys);
2515	}
2516
2517	void BspNodeGeometry::SplitGeometry(BspNodeGeometry &front,
2518	BspNodeGeometry &back,
2519	const Plane3 &splitPlane,
2520	const AxisAlignedBox3 &box,
2521	const float epsilon) const
2522	{
2523	// get cross section of new polygon
2524	Polygon3 *planePoly = box.CrossSection(splitPlane);
2525
2526	// split polygon with all other polygons
2527	planePoly = SplitPolygon(planePoly, epsilon);
2528
2529	//-- new polygon splits all other polygons
2530	for (int i = 0; i < (int)mPolys.size(); ++ i)
2531	{
2532	/// don't use epsilon here to get exact split planes
2533	const int cf =
2534	mPolys[i]->ClassifyPlane(splitPlane, Limits::Small);
2535
2536	switch (cf)
2537	{
2538	case Polygon3::SPLIT:
2539	{
2540	Polygon3 *poly = new Polygon3(mPolys[i]->mVertices);
2541
2542	Polygon3 *frontPoly = new Polygon3();
2543	Polygon3 *backPoly = new Polygon3();
2544
2545	poly->Split(splitPlane,
2546	*frontPoly,
2547	*backPoly,
2548	epsilon);
2549
2550	DEL_PTR(poly);
2551
2552	if (frontPoly->Valid(epsilon))
2553	front.mPolys.push_back(frontPoly);
2554	else
2555	DEL_PTR(frontPoly);
2556
2557	if (backPoly->Valid(epsilon))
2558	back.mPolys.push_back(backPoly);
2559	else
2560	DEL_PTR(backPoly);
2561	}
2562
2563	break;
2564	case Polygon3::BACK_SIDE:
2565	back.mPolys.push_back(new Polygon3(mPolys[i]->mVertices));
2566	break;
2567	case Polygon3::FRONT_SIDE:
2568	front.mPolys.push_back(new Polygon3(mPolys[i]->mVertices));
2569	break;
2570	case Polygon3::COINCIDENT:
2571	//front.mPolys.push_back(CreateReversePolygon(mPolys[i]));
2572	back.mPolys.push_back(new Polygon3(mPolys[i]->mVertices));
2573	break;
2574	default:
2575	break;
2576	}
2577	}
2578
2579	//-- finally add the new polygon to the child node geometries
2580	if (planePoly)
2581	{
2582	// add polygon with normal pointing into positive half space to back cell
2583	back.mPolys.push_back(planePoly);
2584	// add polygon with reverse orientation to front cell
2585	front.mPolys.push_back(planePoly->CreateReversePolygon());
2586	}
2587
2588	//Debug << "returning new geometry " << mPolys.size() << " f: " << front.mPolys.size() << " b: " << back.mPolys.size() << endl;
2589	//Debug << "old area " << GetArea() << " f: " << front.GetArea() << " b: " << back.GetArea() << endl;
2590	}
2591
2592	Polygon3 BspNodeGeometry::SplitPolygon(Polygon3 planePoly,
2593	const float epsilon) const
2594	{
2595	if (!planePoly->Valid(epsilon))
2596	DEL_PTR(planePoly);
2597
2598	// polygon is split by all other planes
2599	for (int i = 0; (i < (int)mPolys.size()) && planePoly; ++ i)
2600	{
2601	Plane3 plane = mPolys[i]->GetSupportingPlane();
2602
2603	/// don't use epsilon here to get exact split planes
2604	const int cf =
2605	planePoly->ClassifyPlane(plane, Limits::Small);
2606
2607	// split new polygon with all previous planes
2608	switch (cf)
2609	{
2610	case Polygon3::SPLIT:
2611	{
2612	Polygon3 *frontPoly = new Polygon3();
2613	Polygon3 *backPoly = new Polygon3();
2614
2615	planePoly->Split(plane,
2616	*frontPoly,
2617	*backPoly,
2618	epsilon);
2619
2620	// don't need anymore
2621	DEL_PTR(planePoly);
2622	DEL_PTR(frontPoly);
2623
2624	// back polygon is belonging to geometry
2625	if (backPoly->Valid(epsilon))
2626	planePoly = backPoly;
2627	else
2628	DEL_PTR(backPoly);
2629	}
2630	break;
2631	case Polygon3::FRONT_SIDE:
2632	DEL_PTR(planePoly);
2633	break;
2634	// polygon is taken as it is
2635	case Polygon3::BACK_SIDE:
2636	case Polygon3::COINCIDENT:
2637	default:
2638	break;
2639	}
2640	}
2641
2642	return planePoly;
2643	}
2644
2645	void BspNodeGeometry::ComputeBoundingBox(AxisAlignedBox3 &box)
2646	{
2647	Polygon3::IncludeInBox(mPolys, box);
2648	}

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