1 // Copyright (C) 2007-2015 CEA/DEN, EDF R&D, OPEN CASCADE
3 // Copyright (C) 2003-2007 OPEN CASCADE, EADS/CCR, LIP6, CEA/DEN,
4 // CEDRAT, EDF R&D, LEG, PRINCIPIA R&D, BUREAU VERITAS
6 // This library is free software; you can redistribute it and/or
7 // modify it under the terms of the GNU Lesser General Public
8 // License as published by the Free Software Foundation; either
9 // version 2.1 of the License, or (at your option) any later version.
11 // This library is distributed in the hope that it will be useful,
12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 // Lesser General Public License for more details.
16 // You should have received a copy of the GNU Lesser General Public
17 // License along with this library; if not, write to the Free Software
18 // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 // See http://www.salome-platform.org/ or email : webmaster.salome@opencascade.com
22 // File : SMESH_MeshAlgos.hxx
23 // Created : Tue Apr 30 18:00:36 2013
24 // Author : Edward AGAPOV (eap)
26 // This file holds some low level algorithms extracted from SMESH_MeshEditor
27 // to make them accessible from Controls package
29 #include "SMESH_MeshAlgos.hxx"
31 #include "SMDS_FaceOfNodes.hxx"
32 #include "SMDS_LinearEdge.hxx"
33 #include "SMDS_Mesh.hxx"
34 #include "SMDS_PolygonalFaceOfNodes.hxx"
35 #include "SMDS_VolumeTool.hxx"
36 #include "SMESH_OctreeNode.hxx"
38 #include <GC_MakeSegment.hxx>
39 #include <GeomAPI_ExtremaCurveCurve.hxx>
40 #include <Geom_Line.hxx>
41 #include <IntAna_IntConicQuad.hxx>
42 #include <IntAna_Quadric.hxx>
51 //=======================================================================
53 * \brief Implementation of search for the node closest to point
55 //=======================================================================
57 struct SMESH_NodeSearcherImpl: public SMESH_NodeSearcher
59 //---------------------------------------------------------------------
63 SMESH_NodeSearcherImpl( const SMDS_Mesh* theMesh )
65 myMesh = ( SMDS_Mesh* ) theMesh;
67 TIDSortedNodeSet nodes;
69 SMDS_NodeIteratorPtr nIt = theMesh->nodesIterator(/*idInceasingOrder=*/true);
71 nodes.insert( nodes.end(), nIt->next() );
73 myOctreeNode = new SMESH_OctreeNode(nodes) ;
75 // get max size of a leaf box
76 SMESH_OctreeNode* tree = myOctreeNode;
77 while ( !tree->isLeaf() )
79 SMESH_OctreeNodeIteratorPtr cIt = tree->GetChildrenIterator();
83 myHalfLeafSize = tree->maxSize() / 2.;
86 //---------------------------------------------------------------------
88 * \brief Move node and update myOctreeNode accordingly
90 void MoveNode( const SMDS_MeshNode* node, const gp_Pnt& toPnt )
92 myOctreeNode->UpdateByMoveNode( node, toPnt );
93 myMesh->MoveNode( node, toPnt.X(), toPnt.Y(), toPnt.Z() );
96 //---------------------------------------------------------------------
100 const SMDS_MeshNode* FindClosestTo( const gp_Pnt& thePnt )
102 map<double, const SMDS_MeshNode*> dist2Nodes;
103 myOctreeNode->NodesAround( thePnt.Coord(), dist2Nodes, myHalfLeafSize );
104 if ( !dist2Nodes.empty() )
105 return dist2Nodes.begin()->second;
106 list<const SMDS_MeshNode*> nodes;
107 //myOctreeNode->NodesAround( &tgtNode, &nodes, myHalfLeafSize );
109 double minSqDist = DBL_MAX;
110 if ( nodes.empty() ) // get all nodes of OctreeNode's closest to thePnt
112 // sort leafs by their distance from thePnt
113 typedef map< double, SMESH_OctreeNode* > TDistTreeMap;
114 TDistTreeMap treeMap;
115 list< SMESH_OctreeNode* > treeList;
116 list< SMESH_OctreeNode* >::iterator trIt;
117 treeList.push_back( myOctreeNode );
119 gp_XYZ pointNode( thePnt.X(), thePnt.Y(), thePnt.Z() );
120 bool pointInside = myOctreeNode->isInside( pointNode, myHalfLeafSize );
121 for ( trIt = treeList.begin(); trIt != treeList.end(); ++trIt)
123 SMESH_OctreeNode* tree = *trIt;
124 if ( !tree->isLeaf() ) // put children to the queue
126 if ( pointInside && !tree->isInside( pointNode, myHalfLeafSize )) continue;
127 SMESH_OctreeNodeIteratorPtr cIt = tree->GetChildrenIterator();
128 while ( cIt->more() )
129 treeList.push_back( cIt->next() );
131 else if ( tree->NbNodes() ) // put a tree to the treeMap
133 const Bnd_B3d& box = *tree->getBox();
134 double sqDist = thePnt.SquareDistance( 0.5 * ( box.CornerMin() + box.CornerMax() ));
135 pair<TDistTreeMap::iterator,bool> it_in = treeMap.insert( make_pair( sqDist, tree ));
136 if ( !it_in.second ) // not unique distance to box center
137 treeMap.insert( it_in.first, make_pair( sqDist + 1e-13*treeMap.size(), tree ));
140 // find distance after which there is no sense to check tree's
141 double sqLimit = DBL_MAX;
142 TDistTreeMap::iterator sqDist_tree = treeMap.begin();
143 if ( treeMap.size() > 5 ) {
144 SMESH_OctreeNode* closestTree = sqDist_tree->second;
145 const Bnd_B3d& box = *closestTree->getBox();
146 double limit = sqrt( sqDist_tree->first ) + sqrt ( box.SquareExtent() );
147 sqLimit = limit * limit;
149 // get all nodes from trees
150 for ( ; sqDist_tree != treeMap.end(); ++sqDist_tree) {
151 if ( sqDist_tree->first > sqLimit )
153 SMESH_OctreeNode* tree = sqDist_tree->second;
154 tree->NodesAround( tree->GetNodeIterator()->next(), &nodes );
157 // find closest among nodes
159 const SMDS_MeshNode* closestNode = 0;
160 list<const SMDS_MeshNode*>::iterator nIt = nodes.begin();
161 for ( ; nIt != nodes.end(); ++nIt ) {
162 double sqDist = thePnt.SquareDistance( SMESH_TNodeXYZ( *nIt ) );
163 if ( minSqDist > sqDist ) {
171 //---------------------------------------------------------------------
173 * \brief Finds nodes located within a tolerance near a point
175 int FindNearPoint(const gp_Pnt& point,
176 const double tolerance,
177 std::vector< const SMDS_MeshNode* >& foundNodes)
179 myOctreeNode->NodesAround( point.Coord(), foundNodes, tolerance );
180 return foundNodes.size();
183 //---------------------------------------------------------------------
187 ~SMESH_NodeSearcherImpl() { delete myOctreeNode; }
189 //---------------------------------------------------------------------
191 * \brief Return the node tree
193 const SMESH_OctreeNode* getTree() const { return myOctreeNode; }
196 SMESH_OctreeNode* myOctreeNode;
198 double myHalfLeafSize; // max size of a leaf box
201 // ========================================================================
202 namespace // Utils used in SMESH_ElementSearcherImpl::FindElementsByPoint()
204 const int MaxNbElemsInLeaf = 10; // maximal number of elements in a leaf of tree
205 const int MaxLevel = 7; // maximal tree height -> nb terminal boxes: 8^7 = 2097152
206 const double NodeRadius = 1e-9; // to enlarge bnd box of element
208 //=======================================================================
210 * \brief Octal tree of bounding boxes of elements
212 //=======================================================================
214 class ElementBndBoxTree : public SMESH_Octree
218 ElementBndBoxTree(const SMDS_Mesh& mesh,
219 SMDSAbs_ElementType elemType,
220 SMDS_ElemIteratorPtr theElemIt = SMDS_ElemIteratorPtr(),
221 double tolerance = NodeRadius );
222 void getElementsNearPoint( const gp_Pnt& point, TIDSortedElemSet& foundElems );
223 void getElementsNearLine ( const gp_Ax1& line, TIDSortedElemSet& foundElems);
224 void getElementsInSphere ( const gp_XYZ& center,
225 const double radius, TIDSortedElemSet& foundElems);
226 size_t getSize() { return std::max( _size, _elements.size() ); }
227 virtual ~ElementBndBoxTree();
230 ElementBndBoxTree():_size(0) {}
231 SMESH_Octree* newChild() const { return new ElementBndBoxTree; }
232 void buildChildrenData();
233 Bnd_B3d* buildRootBox();
235 //!< Bounding box of element
236 struct ElementBox : public Bnd_B3d
238 const SMDS_MeshElement* _element;
239 int _refCount; // an ElementBox can be included in several tree branches
240 ElementBox(const SMDS_MeshElement* elem, double tolerance);
242 vector< ElementBox* > _elements;
246 //================================================================================
248 * \brief ElementBndBoxTree creation
250 //================================================================================
252 ElementBndBoxTree::ElementBndBoxTree(const SMDS_Mesh& mesh, SMDSAbs_ElementType elemType, SMDS_ElemIteratorPtr theElemIt, double tolerance)
253 :SMESH_Octree( new SMESH_TreeLimit( MaxLevel, /*minSize=*/0. ))
255 int nbElems = mesh.GetMeshInfo().NbElements( elemType );
256 _elements.reserve( nbElems );
258 SMDS_ElemIteratorPtr elemIt = theElemIt ? theElemIt : mesh.elementsIterator( elemType );
259 while ( elemIt->more() )
260 _elements.push_back( new ElementBox( elemIt->next(),tolerance ));
265 //================================================================================
269 //================================================================================
271 ElementBndBoxTree::~ElementBndBoxTree()
273 for ( int i = 0; i < _elements.size(); ++i )
274 if ( --_elements[i]->_refCount <= 0 )
278 //================================================================================
280 * \brief Return the maximal box
282 //================================================================================
284 Bnd_B3d* ElementBndBoxTree::buildRootBox()
286 Bnd_B3d* box = new Bnd_B3d;
287 for ( int i = 0; i < _elements.size(); ++i )
288 box->Add( *_elements[i] );
292 //================================================================================
294 * \brief Redistrubute element boxes among children
296 //================================================================================
298 void ElementBndBoxTree::buildChildrenData()
300 for ( int i = 0; i < _elements.size(); ++i )
302 for (int j = 0; j < 8; j++)
304 if ( !_elements[i]->IsOut( *myChildren[j]->getBox() ))
306 _elements[i]->_refCount++;
307 ((ElementBndBoxTree*)myChildren[j])->_elements.push_back( _elements[i]);
310 _elements[i]->_refCount--;
312 _size = _elements.size();
313 SMESHUtils::FreeVector( _elements ); // = _elements.clear() + free memory
315 for (int j = 0; j < 8; j++)
317 ElementBndBoxTree* child = static_cast<ElementBndBoxTree*>( myChildren[j]);
318 if ( child->_elements.size() <= MaxNbElemsInLeaf )
319 child->myIsLeaf = true;
321 if ( child->_elements.capacity() - child->_elements.size() > 1000 )
322 SMESHUtils::CompactVector( child->_elements );
326 //================================================================================
328 * \brief Return elements which can include the point
330 //================================================================================
332 void ElementBndBoxTree::getElementsNearPoint( const gp_Pnt& point,
333 TIDSortedElemSet& foundElems)
335 if ( getBox()->IsOut( point.XYZ() ))
340 for ( int i = 0; i < _elements.size(); ++i )
341 if ( !_elements[i]->IsOut( point.XYZ() ))
342 foundElems.insert( _elements[i]->_element );
346 for (int i = 0; i < 8; i++)
347 ((ElementBndBoxTree*) myChildren[i])->getElementsNearPoint( point, foundElems );
351 //================================================================================
353 * \brief Return elements which can be intersected by the line
355 //================================================================================
357 void ElementBndBoxTree::getElementsNearLine( const gp_Ax1& line,
358 TIDSortedElemSet& foundElems)
360 if ( getBox()->IsOut( line ))
365 for ( int i = 0; i < _elements.size(); ++i )
366 if ( !_elements[i]->IsOut( line ))
367 foundElems.insert( _elements[i]->_element );
371 for (int i = 0; i < 8; i++)
372 ((ElementBndBoxTree*) myChildren[i])->getElementsNearLine( line, foundElems );
376 //================================================================================
378 * \brief Return elements from leaves intersecting the sphere
380 //================================================================================
382 void ElementBndBoxTree::getElementsInSphere ( const gp_XYZ& center,
384 TIDSortedElemSet& foundElems)
386 if ( getBox()->IsOut( center, radius ))
391 for ( int i = 0; i < _elements.size(); ++i )
392 if ( !_elements[i]->IsOut( center, radius ))
393 foundElems.insert( _elements[i]->_element );
397 for (int i = 0; i < 8; i++)
398 ((ElementBndBoxTree*) myChildren[i])->getElementsInSphere( center, radius, foundElems );
402 //================================================================================
404 * \brief Construct the element box
406 //================================================================================
408 ElementBndBoxTree::ElementBox::ElementBox(const SMDS_MeshElement* elem, double tolerance)
412 SMDS_ElemIteratorPtr nIt = elem->nodesIterator();
413 while ( nIt->more() )
414 Add( SMESH_TNodeXYZ( nIt->next() ));
415 Enlarge( tolerance );
420 //=======================================================================
422 * \brief Implementation of search for the elements by point and
423 * of classification of point in 2D mesh
425 //=======================================================================
427 SMESH_ElementSearcher::~SMESH_ElementSearcher()
431 struct SMESH_ElementSearcherImpl: public SMESH_ElementSearcher
434 SMDS_ElemIteratorPtr _meshPartIt;
435 ElementBndBoxTree* _ebbTree;
436 SMESH_NodeSearcherImpl* _nodeSearcher;
437 SMDSAbs_ElementType _elementType;
439 bool _outerFacesFound;
440 set<const SMDS_MeshElement*> _outerFaces; // empty means "no internal faces at all"
442 SMESH_ElementSearcherImpl( SMDS_Mesh& mesh,
444 SMDS_ElemIteratorPtr elemIt=SMDS_ElemIteratorPtr())
445 : _mesh(&mesh),_meshPartIt(elemIt),_ebbTree(0),_nodeSearcher(0),_tolerance(tol),_outerFacesFound(false) {}
446 virtual ~SMESH_ElementSearcherImpl()
448 if ( _ebbTree ) delete _ebbTree; _ebbTree = 0;
449 if ( _nodeSearcher ) delete _nodeSearcher; _nodeSearcher = 0;
451 virtual int FindElementsByPoint(const gp_Pnt& point,
452 SMDSAbs_ElementType type,
453 vector< const SMDS_MeshElement* >& foundElements);
454 virtual TopAbs_State GetPointState(const gp_Pnt& point);
455 virtual const SMDS_MeshElement* FindClosestTo( const gp_Pnt& point,
456 SMDSAbs_ElementType type );
458 void GetElementsNearLine( const gp_Ax1& line,
459 SMDSAbs_ElementType type,
460 vector< const SMDS_MeshElement* >& foundElems);
461 double getTolerance();
462 bool getIntersParamOnLine(const gp_Lin& line, const SMDS_MeshElement* face,
463 const double tolerance, double & param);
464 void findOuterBoundary(const SMDS_MeshElement* anyOuterFace);
465 bool isOuterBoundary(const SMDS_MeshElement* face) const
467 return _outerFaces.empty() || _outerFaces.count(face);
469 struct TInters //!< data of intersection of the line and the mesh face (used in GetPointState())
471 const SMDS_MeshElement* _face;
473 bool _coincides; //!< the line lays in face plane
474 TInters(const SMDS_MeshElement* face, const gp_Vec& faceNorm, bool coinc=false)
475 : _face(face), _faceNorm( faceNorm ), _coincides( coinc ) {}
477 struct TFaceLink //!< link and faces sharing it (used in findOuterBoundary())
480 TIDSortedElemSet _faces;
481 TFaceLink( const SMDS_MeshNode* n1, const SMDS_MeshNode* n2, const SMDS_MeshElement* face)
482 : _link( n1, n2 ), _faces( &face, &face + 1) {}
486 ostream& operator<< (ostream& out, const SMESH_ElementSearcherImpl::TInters& i)
488 return out << "TInters(face=" << ( i._face ? i._face->GetID() : 0)
489 << ", _coincides="<<i._coincides << ")";
492 //=======================================================================
494 * \brief define tolerance for search
496 //=======================================================================
498 double SMESH_ElementSearcherImpl::getTolerance()
500 if ( _tolerance < 0 )
502 const SMDS_MeshInfo& meshInfo = _mesh->GetMeshInfo();
505 if ( _nodeSearcher && meshInfo.NbNodes() > 1 )
507 double boxSize = _nodeSearcher->getTree()->maxSize();
508 _tolerance = 1e-8 * boxSize/* / meshInfo.NbNodes()*/;
510 else if ( _ebbTree && meshInfo.NbElements() > 0 )
512 double boxSize = _ebbTree->maxSize();
513 _tolerance = 1e-8 * boxSize/* / meshInfo.NbElements()*/;
515 if ( _tolerance == 0 )
517 // define tolerance by size of a most complex element
518 int complexType = SMDSAbs_Volume;
519 while ( complexType > SMDSAbs_All &&
520 meshInfo.NbElements( SMDSAbs_ElementType( complexType )) < 1 )
522 if ( complexType == SMDSAbs_All ) return 0; // empty mesh
524 if ( complexType == int( SMDSAbs_Node ))
526 SMDS_NodeIteratorPtr nodeIt = _mesh->nodesIterator();
528 if ( meshInfo.NbNodes() > 2 )
529 elemSize = SMESH_TNodeXYZ( nodeIt->next() ).Distance( nodeIt->next() );
533 SMDS_ElemIteratorPtr elemIt =
534 _mesh->elementsIterator( SMDSAbs_ElementType( complexType ));
535 const SMDS_MeshElement* elem = elemIt->next();
536 SMDS_ElemIteratorPtr nodeIt = elem->nodesIterator();
537 SMESH_TNodeXYZ n1( nodeIt->next() );
539 while ( nodeIt->more() )
541 double dist = n1.Distance( static_cast<const SMDS_MeshNode*>( nodeIt->next() ));
542 elemSize = max( dist, elemSize );
545 _tolerance = 1e-4 * elemSize;
551 //================================================================================
553 * \brief Find intersection of the line and an edge of face and return parameter on line
555 //================================================================================
557 bool SMESH_ElementSearcherImpl::getIntersParamOnLine(const gp_Lin& line,
558 const SMDS_MeshElement* face,
565 GeomAPI_ExtremaCurveCurve anExtCC;
566 Handle(Geom_Curve) lineCurve = new Geom_Line( line );
568 int nbNodes = face->IsQuadratic() ? face->NbNodes()/2 : face->NbNodes();
569 for ( int i = 0; i < nbNodes && nbInts < 2; ++i )
571 GC_MakeSegment edge( SMESH_TNodeXYZ( face->GetNode( i )),
572 SMESH_TNodeXYZ( face->GetNode( (i+1)%nbNodes) ));
573 anExtCC.Init( lineCurve, edge);
574 if ( anExtCC.NbExtrema() > 0 && anExtCC.LowerDistance() <= tol)
576 Quantity_Parameter pl, pe;
577 anExtCC.LowerDistanceParameters( pl, pe );
583 if ( nbInts > 0 ) param /= nbInts;
586 //================================================================================
588 * \brief Find all faces belonging to the outer boundary of mesh
590 //================================================================================
592 void SMESH_ElementSearcherImpl::findOuterBoundary(const SMDS_MeshElement* outerFace)
594 if ( _outerFacesFound ) return;
596 // Collect all outer faces by passing from one outer face to another via their links
597 // and BTW find out if there are internal faces at all.
599 // checked links and links where outer boundary meets internal one
600 set< SMESH_TLink > visitedLinks, seamLinks;
602 // links to treat with already visited faces sharing them
603 list < TFaceLink > startLinks;
605 // load startLinks with the first outerFace
606 startLinks.push_back( TFaceLink( outerFace->GetNode(0), outerFace->GetNode(1), outerFace));
607 _outerFaces.insert( outerFace );
609 TIDSortedElemSet emptySet;
610 while ( !startLinks.empty() )
612 const SMESH_TLink& link = startLinks.front()._link;
613 TIDSortedElemSet& faces = startLinks.front()._faces;
615 outerFace = *faces.begin();
616 // find other faces sharing the link
617 const SMDS_MeshElement* f;
618 while (( f = SMESH_MeshAlgos::FindFaceInSet(link.node1(), link.node2(), emptySet, faces )))
621 // select another outer face among the found
622 const SMDS_MeshElement* outerFace2 = 0;
623 if ( faces.size() == 2 )
625 outerFace2 = (outerFace == *faces.begin() ? *faces.rbegin() : *faces.begin());
627 else if ( faces.size() > 2 )
629 seamLinks.insert( link );
631 // link direction within the outerFace
632 gp_Vec n1n2( SMESH_TNodeXYZ( link.node1()),
633 SMESH_TNodeXYZ( link.node2()));
634 int i1 = outerFace->GetNodeIndex( link.node1() );
635 int i2 = outerFace->GetNodeIndex( link.node2() );
636 bool rev = ( abs(i2-i1) == 1 ? i1 > i2 : i2 > i1 );
637 if ( rev ) n1n2.Reverse();
639 gp_XYZ ofNorm, fNorm;
640 if ( SMESH_MeshAlgos::FaceNormal( outerFace, ofNorm, /*normalized=*/false ))
642 // direction from the link inside outerFace
643 gp_Vec dirInOF = gp_Vec( ofNorm ) ^ n1n2;
644 // sort all other faces by angle with the dirInOF
645 map< double, const SMDS_MeshElement* > angle2Face;
646 set< const SMDS_MeshElement*, TIDCompare >::const_iterator face = faces.begin();
647 for ( ; face != faces.end(); ++face )
649 if ( !SMESH_MeshAlgos::FaceNormal( *face, fNorm, /*normalized=*/false ))
651 gp_Vec dirInF = gp_Vec( fNorm ) ^ n1n2;
652 double angle = dirInOF.AngleWithRef( dirInF, n1n2 );
653 if ( angle < 0 ) angle += 2. * M_PI;
654 angle2Face.insert( make_pair( angle, *face ));
656 if ( !angle2Face.empty() )
657 outerFace2 = angle2Face.begin()->second;
660 // store the found outer face and add its links to continue seaching from
663 _outerFaces.insert( outerFace );
664 int nbNodes = outerFace2->NbNodes()/( outerFace2->IsQuadratic() ? 2 : 1 );
665 for ( int i = 0; i < nbNodes; ++i )
667 SMESH_TLink link2( outerFace2->GetNode(i), outerFace2->GetNode((i+1)%nbNodes));
668 if ( visitedLinks.insert( link2 ).second )
669 startLinks.push_back( TFaceLink( link2.node1(), link2.node2(), outerFace2 ));
672 startLinks.pop_front();
674 _outerFacesFound = true;
676 if ( !seamLinks.empty() )
678 // There are internal boundaries touching the outher one,
679 // find all faces of internal boundaries in order to find
680 // faces of boundaries of holes, if any.
689 //=======================================================================
691 * \brief Find elements of given type where the given point is IN or ON.
692 * Returns nb of found elements and elements them-selves.
694 * 'ALL' type means elements of any type excluding nodes, balls and 0D elements
696 //=======================================================================
698 int SMESH_ElementSearcherImpl::
699 FindElementsByPoint(const gp_Pnt& point,
700 SMDSAbs_ElementType type,
701 vector< const SMDS_MeshElement* >& foundElements)
703 foundElements.clear();
705 double tolerance = getTolerance();
707 // =================================================================================
708 if ( type == SMDSAbs_Node || type == SMDSAbs_0DElement || type == SMDSAbs_Ball)
710 if ( !_nodeSearcher )
711 _nodeSearcher = new SMESH_NodeSearcherImpl( _mesh );
713 std::vector< const SMDS_MeshNode* > foundNodes;
714 _nodeSearcher->FindNearPoint( point, tolerance, foundNodes );
716 if ( type == SMDSAbs_Node )
718 foundElements.assign( foundNodes.begin(), foundNodes.end() );
722 for ( size_t i = 0; i < foundNodes.size(); ++i )
724 SMDS_ElemIteratorPtr elemIt = foundNodes[i]->GetInverseElementIterator( type );
725 while ( elemIt->more() )
726 foundElements.push_back( elemIt->next() );
730 // =================================================================================
731 else // elements more complex than 0D
733 if ( !_ebbTree || _elementType != type )
735 if ( _ebbTree ) delete _ebbTree;
736 _ebbTree = new ElementBndBoxTree( *_mesh, _elementType = type, _meshPartIt, tolerance );
738 TIDSortedElemSet suspectElems;
739 _ebbTree->getElementsNearPoint( point, suspectElems );
740 TIDSortedElemSet::iterator elem = suspectElems.begin();
741 for ( ; elem != suspectElems.end(); ++elem )
742 if ( !SMESH_MeshAlgos::IsOut( *elem, point, tolerance ))
743 foundElements.push_back( *elem );
745 return foundElements.size();
748 //=======================================================================
750 * \brief Find an element of given type most close to the given point
752 * WARNING: Only face search is implemeneted so far
754 //=======================================================================
756 const SMDS_MeshElement*
757 SMESH_ElementSearcherImpl::FindClosestTo( const gp_Pnt& point,
758 SMDSAbs_ElementType type )
760 const SMDS_MeshElement* closestElem = 0;
762 if ( type == SMDSAbs_Face || type == SMDSAbs_Volume )
764 if ( !_ebbTree || _elementType != type )
766 if ( _ebbTree ) delete _ebbTree;
767 _ebbTree = new ElementBndBoxTree( *_mesh, _elementType = type, _meshPartIt );
769 TIDSortedElemSet suspectElems;
770 _ebbTree->getElementsNearPoint( point, suspectElems );
772 if ( suspectElems.empty() && _ebbTree->maxSize() > 0 )
774 gp_Pnt boxCenter = 0.5 * ( _ebbTree->getBox()->CornerMin() +
775 _ebbTree->getBox()->CornerMax() );
777 if ( _ebbTree->getBox()->IsOut( point.XYZ() ))
778 radius = point.Distance( boxCenter ) - 0.5 * _ebbTree->maxSize();
780 radius = _ebbTree->maxSize() / pow( 2., _ebbTree->getHeight()) / 2;
781 while ( suspectElems.empty() )
783 _ebbTree->getElementsInSphere( point.XYZ(), radius, suspectElems );
787 double minDist = std::numeric_limits<double>::max();
788 multimap< double, const SMDS_MeshElement* > dist2face;
789 TIDSortedElemSet::iterator elem = suspectElems.begin();
790 for ( ; elem != suspectElems.end(); ++elem )
792 double dist = SMESH_MeshAlgos::GetDistance( *elem, point );
793 if ( dist < minDist + 1e-10)
796 dist2face.insert( dist2face.begin(), make_pair( dist, *elem ));
799 if ( !dist2face.empty() )
801 multimap< double, const SMDS_MeshElement* >::iterator d2f = dist2face.begin();
802 closestElem = d2f->second;
803 // if there are several elements at the same distance, select one
804 // with GC closest to the point
805 typedef SMDS_StdIterator< SMESH_TNodeXYZ, SMDS_ElemIteratorPtr > TXyzIterator;
806 double minDistToGC = 0;
807 for ( ++d2f; d2f != dist2face.end() && fabs( d2f->first - minDist ) < 1e-10; ++d2f )
809 if ( minDistToGC == 0 )
812 gc = accumulate( TXyzIterator(closestElem->nodesIterator()),
813 TXyzIterator(), gc ) / closestElem->NbNodes();
814 minDistToGC = point.SquareDistance( gc );
817 gc = accumulate( TXyzIterator( d2f->second->nodesIterator()),
818 TXyzIterator(), gc ) / d2f->second->NbNodes();
819 double d = point.SquareDistance( gc );
820 if ( d < minDistToGC )
823 closestElem = d2f->second;
826 // cout << "FindClosestTo( " <<point.X()<<", "<<point.Y()<<", "<<point.Z()<<" ) FACE "
827 // <<closestElem->GetID() << " DIST " << minDist << endl;
832 // NOT IMPLEMENTED SO FAR
838 //================================================================================
840 * \brief Classify the given point in the closed 2D mesh
842 //================================================================================
844 TopAbs_State SMESH_ElementSearcherImpl::GetPointState(const gp_Pnt& point)
846 double tolerance = getTolerance();
847 if ( !_ebbTree || _elementType != SMDSAbs_Face )
849 if ( _ebbTree ) delete _ebbTree;
850 _ebbTree = new ElementBndBoxTree( *_mesh, _elementType = SMDSAbs_Face, _meshPartIt );
852 // Algo: analyse transition of a line starting at the point through mesh boundary;
853 // try three lines parallel to axis of the coordinate system and perform rough
854 // analysis. If solution is not clear perform thorough analysis.
856 const int nbAxes = 3;
857 gp_Dir axisDir[ nbAxes ] = { gp::DX(), gp::DY(), gp::DZ() };
858 map< double, TInters > paramOnLine2TInters[ nbAxes ];
859 list< TInters > tangentInters[ nbAxes ]; // of faces whose plane includes the line
860 multimap< int, int > nbInt2Axis; // to find the simplest case
861 for ( int axis = 0; axis < nbAxes; ++axis )
863 gp_Ax1 lineAxis( point, axisDir[axis]);
864 gp_Lin line ( lineAxis );
866 TIDSortedElemSet suspectFaces; // faces possibly intersecting the line
867 _ebbTree->getElementsNearLine( lineAxis, suspectFaces );
869 // Intersect faces with the line
871 map< double, TInters > & u2inters = paramOnLine2TInters[ axis ];
872 TIDSortedElemSet::iterator face = suspectFaces.begin();
873 for ( ; face != suspectFaces.end(); ++face )
877 if ( !SMESH_MeshAlgos::FaceNormal( *face, fNorm, /*normalized=*/false)) continue;
878 gp_Pln facePlane( SMESH_TNodeXYZ( (*face)->GetNode(0)), fNorm );
880 // perform intersection
881 IntAna_IntConicQuad intersection( line, IntAna_Quadric( facePlane ));
882 if ( !intersection.IsDone() )
884 if ( intersection.IsInQuadric() )
886 tangentInters[ axis ].push_back( TInters( *face, fNorm, true ));
888 else if ( ! intersection.IsParallel() && intersection.NbPoints() > 0 )
890 gp_Pnt intersectionPoint = intersection.Point(1);
891 if ( !SMESH_MeshAlgos::IsOut( *face, intersectionPoint, tolerance ))
892 u2inters.insert(make_pair( intersection.ParamOnConic(1), TInters( *face, fNorm )));
895 // Analyse intersections roughly
897 int nbInter = u2inters.size();
901 double f = u2inters.begin()->first, l = u2inters.rbegin()->first;
902 if ( nbInter == 1 ) // not closed mesh
903 return fabs( f ) < tolerance ? TopAbs_ON : TopAbs_UNKNOWN;
905 if ( fabs( f ) < tolerance || fabs( l ) < tolerance )
908 if ( (f<0) == (l<0) )
911 int nbIntBeforePoint = std::distance( u2inters.begin(), u2inters.lower_bound(0));
912 int nbIntAfterPoint = nbInter - nbIntBeforePoint;
913 if ( nbIntBeforePoint == 1 || nbIntAfterPoint == 1 )
916 nbInt2Axis.insert( make_pair( min( nbIntBeforePoint, nbIntAfterPoint ), axis ));
918 if ( _outerFacesFound ) break; // pass to thorough analysis
920 } // three attempts - loop on CS axes
922 // Analyse intersections thoroughly.
923 // We make two loops maximum, on the first one we only exclude touching intersections,
924 // on the second, if situation is still unclear, we gather and use information on
925 // position of faces (internal or outer). If faces position is already gathered,
926 // we make the second loop right away.
928 for ( int hasPositionInfo = _outerFacesFound; hasPositionInfo < 2; ++hasPositionInfo )
930 multimap< int, int >::const_iterator nb_axis = nbInt2Axis.begin();
931 for ( ; nb_axis != nbInt2Axis.end(); ++nb_axis )
933 int axis = nb_axis->second;
934 map< double, TInters > & u2inters = paramOnLine2TInters[ axis ];
936 gp_Ax1 lineAxis( point, axisDir[axis]);
937 gp_Lin line ( lineAxis );
939 // add tangent intersections to u2inters
941 list< TInters >::const_iterator tgtInt = tangentInters[ axis ].begin();
942 for ( ; tgtInt != tangentInters[ axis ].end(); ++tgtInt )
943 if ( getIntersParamOnLine( line, tgtInt->_face, tolerance, param ))
944 u2inters.insert(make_pair( param, *tgtInt ));
945 tangentInters[ axis ].clear();
947 // Count intersections before and after the point excluding touching ones.
948 // If hasPositionInfo we count intersections of outer boundary only
950 int nbIntBeforePoint = 0, nbIntAfterPoint = 0;
951 double f = numeric_limits<double>::max(), l = -numeric_limits<double>::max();
952 map< double, TInters >::iterator u_int1 = u2inters.begin(), u_int2 = u_int1;
953 bool ok = ! u_int1->second._coincides;
954 while ( ok && u_int1 != u2inters.end() )
956 double u = u_int1->first;
957 bool touchingInt = false;
958 if ( ++u_int2 != u2inters.end() )
960 // skip intersections at the same point (if the line passes through edge or node)
962 while ( u_int2 != u2inters.end() && fabs( u_int2->first - u ) < tolerance )
968 // skip tangent intersections
970 const SMDS_MeshElement* prevFace = u_int1->second._face;
971 while ( ok && u_int2->second._coincides )
973 if ( SMESH_MeshAlgos::GetCommonNodes(prevFace , u_int2->second._face).empty() )
979 ok = ( u_int2 != u2inters.end() );
984 // skip intersections at the same point after tangent intersections
987 double u2 = u_int2->first;
989 while ( u_int2 != u2inters.end() && fabs( u_int2->first - u2 ) < tolerance )
995 // decide if we skipped a touching intersection
996 if ( nbSamePnt + nbTgt > 0 )
998 double minDot = numeric_limits<double>::max(), maxDot = -numeric_limits<double>::max();
999 map< double, TInters >::iterator u_int = u_int1;
1000 for ( ; u_int != u_int2; ++u_int )
1002 if ( u_int->second._coincides ) continue;
1003 double dot = u_int->second._faceNorm * line.Direction();
1004 if ( dot > maxDot ) maxDot = dot;
1005 if ( dot < minDot ) minDot = dot;
1007 touchingInt = ( minDot*maxDot < 0 );
1012 if ( !hasPositionInfo || isOuterBoundary( u_int1->second._face ))
1023 u_int1 = u_int2; // to next intersection
1025 } // loop on intersections with one line
1029 if ( fabs( f ) < tolerance || fabs( l ) < tolerance )
1032 if ( nbIntBeforePoint == 0 || nbIntAfterPoint == 0)
1035 if ( nbIntBeforePoint + nbIntAfterPoint == 1 ) // not closed mesh
1036 return fabs( f ) < tolerance ? TopAbs_ON : TopAbs_UNKNOWN;
1038 if ( nbIntBeforePoint == 1 || nbIntAfterPoint == 1 )
1041 if ( (f<0) == (l<0) )
1044 if ( hasPositionInfo )
1045 return nbIntBeforePoint % 2 ? TopAbs_IN : TopAbs_OUT;
1047 } // loop on intersections of the tree lines - thorough analysis
1049 if ( !hasPositionInfo )
1051 // gather info on faces position - is face in the outer boundary or not
1052 map< double, TInters > & u2inters = paramOnLine2TInters[ 0 ];
1053 findOuterBoundary( u2inters.begin()->second._face );
1056 } // two attempts - with and w/o faces position info in the mesh
1058 return TopAbs_UNKNOWN;
1061 //=======================================================================
1063 * \brief Return elements possibly intersecting the line
1065 //=======================================================================
1067 void SMESH_ElementSearcherImpl::GetElementsNearLine( const gp_Ax1& line,
1068 SMDSAbs_ElementType type,
1069 vector< const SMDS_MeshElement* >& foundElems)
1071 if ( !_ebbTree || _elementType != type )
1073 if ( _ebbTree ) delete _ebbTree;
1074 _ebbTree = new ElementBndBoxTree( *_mesh, _elementType = type, _meshPartIt );
1076 TIDSortedElemSet suspectFaces; // elements possibly intersecting the line
1077 _ebbTree->getElementsNearLine( line, suspectFaces );
1078 foundElems.assign( suspectFaces.begin(), suspectFaces.end());
1081 //=======================================================================
1083 * \brief Return true if the point is IN or ON of the element
1085 //=======================================================================
1087 bool SMESH_MeshAlgos::IsOut( const SMDS_MeshElement* element, const gp_Pnt& point, double tol )
1089 if ( element->GetType() == SMDSAbs_Volume)
1091 return SMDS_VolumeTool( element ).IsOut( point.X(), point.Y(), point.Z(), tol );
1094 // get ordered nodes
1096 vector< SMESH_TNodeXYZ > xyz;
1098 SMDS_ElemIteratorPtr nodeIt = element->interlacedNodesElemIterator();
1099 while ( nodeIt->more() )
1101 SMESH_TNodeXYZ node = nodeIt->next();
1102 xyz.push_back( node );
1105 int i, nbNodes = (int) xyz.size(); // central node of biquadratic is missing
1107 if ( element->GetType() == SMDSAbs_Face ) // --------------------------------------------------
1109 // compute face normal
1110 gp_Vec faceNorm(0,0,0);
1111 xyz.push_back( xyz.front() );
1112 for ( i = 0; i < nbNodes; ++i )
1114 gp_Vec edge1( xyz[i+1], xyz[i]);
1115 gp_Vec edge2( xyz[i+1], xyz[(i+2)%nbNodes] );
1116 faceNorm += edge1 ^ edge2;
1118 double normSize = faceNorm.Magnitude();
1119 if ( normSize <= tol )
1121 // degenerated face: point is out if it is out of all face edges
1122 for ( i = 0; i < nbNodes; ++i )
1124 SMDS_LinearEdge edge( xyz[i]._node, xyz[i+1]._node );
1125 if ( !IsOut( &edge, point, tol ))
1130 faceNorm /= normSize;
1132 // check if the point lays on face plane
1133 gp_Vec n2p( xyz[0], point );
1134 if ( fabs( n2p * faceNorm ) > tol )
1135 return true; // not on face plane
1137 // check if point is out of face boundary:
1138 // define it by closest transition of a ray point->infinity through face boundary
1139 // on the face plane.
1140 // First, find normal of a plane perpendicular to face plane, to be used as a cutting tool
1141 // to find intersections of the ray with the boundary.
1143 gp_Vec plnNorm = ray ^ faceNorm;
1144 normSize = plnNorm.Magnitude();
1145 if ( normSize <= tol ) return false; // point coincides with the first node
1146 plnNorm /= normSize;
1147 // for each node of the face, compute its signed distance to the plane
1148 vector<double> dist( nbNodes + 1);
1149 for ( i = 0; i < nbNodes; ++i )
1151 gp_Vec n2p( xyz[i], point );
1152 dist[i] = n2p * plnNorm;
1154 dist.back() = dist.front();
1155 // find the closest intersection
1157 double rClosest, distClosest = 1e100;;
1159 for ( i = 0; i < nbNodes; ++i )
1162 if ( fabs( dist[i]) < tol )
1164 else if ( fabs( dist[i+1]) < tol )
1166 else if ( dist[i] * dist[i+1] < 0 )
1167 r = dist[i] / ( dist[i] - dist[i+1] );
1169 continue; // no intersection
1170 gp_Pnt pInt = xyz[i] * (1.-r) + xyz[i+1] * r;
1171 gp_Vec p2int ( point, pInt);
1172 if ( p2int * ray > -tol ) // right half-space
1174 double intDist = p2int.SquareMagnitude();
1175 if ( intDist < distClosest )
1180 distClosest = intDist;
1185 return true; // no intesections - out
1187 // analyse transition
1188 gp_Vec edge( xyz[iClosest], xyz[iClosest+1] );
1189 gp_Vec edgeNorm = -( edge ^ faceNorm ); // normal to intersected edge pointing out of face
1190 gp_Vec p2int ( point, pClosest );
1191 bool out = (edgeNorm * p2int) < -tol;
1192 if ( rClosest > 0. && rClosest < 1. ) // not node intersection
1195 // ray pass through a face node; analyze transition through an adjacent edge
1196 gp_Pnt p1 = xyz[ (rClosest == 0.) ? ((iClosest+nbNodes-1) % nbNodes) : (iClosest+1) ];
1197 gp_Pnt p2 = xyz[ (rClosest == 0.) ? iClosest : ((iClosest+2) % nbNodes) ];
1198 gp_Vec edgeAdjacent( p1, p2 );
1199 gp_Vec edgeNorm2 = -( edgeAdjacent ^ faceNorm );
1200 bool out2 = (edgeNorm2 * p2int) < -tol;
1202 bool covexCorner = ( edgeNorm * edgeAdjacent * (rClosest==1. ? 1. : -1.)) < 0;
1203 return covexCorner ? (out || out2) : (out && out2);
1205 if ( element->GetType() == SMDSAbs_Edge ) // --------------------------------------------------
1207 // point is out of edge if it is NOT ON any straight part of edge
1208 // (we consider quadratic edge as being composed of two straight parts)
1209 for ( i = 1; i < nbNodes; ++i )
1211 gp_Vec edge( xyz[i-1], xyz[i] );
1212 gp_Vec n1p ( xyz[i-1], point );
1213 double u = ( edge * n1p ) / edge.SquareMagnitude(); // param [0,1] on the edge
1215 if ( n1p.SquareMagnitude() < tol * tol )
1220 if ( point.SquareDistance( xyz[i] ) < tol * tol )
1224 gp_XYZ proj = ( 1. - u ) * xyz[i-1] + u * xyz[i]; // projection of the point on the edge
1225 double dist2 = point.SquareDistance( proj );
1226 if ( dist2 > tol * tol )
1228 return false; // point is ON this part
1232 // Node or 0D element -------------------------------------------------------------------------
1234 gp_Vec n2p ( xyz[0], point );
1235 return n2p.SquareMagnitude() <= tol * tol;
1240 //=======================================================================
1243 // Position of a point relative to a segment
1247 // VERTEX 1 o----ON-----> VERTEX 2
1251 enum PositionName { POS_LEFT = 1, POS_VERTEX = 2, POS_RIGHT = 4, //POS_ON = 8,
1252 POS_ALL = POS_LEFT | POS_RIGHT | POS_VERTEX };
1256 int _index; // index of vertex or segment
1258 PointPos( PositionName n, int i=-1 ): _name(n), _index(i) {}
1259 bool operator < (const PointPos& other ) const
1261 if ( _name == other._name )
1262 return ( _index < 0 || other._index < 0 ) ? false : _index < other._index;
1263 return _name < other._name;
1267 //================================================================================
1269 * \brief Return of a point relative to a segment
1270 * \param point2D - the point to analyze position of
1271 * \param xyVec - end points of segments
1272 * \param index0 - 0-based index of the first point of segment
1273 * \param posToFindOut - flags of positions to detect
1274 * \retval PointPos - point position
1276 //================================================================================
1278 PointPos getPointPosition( const gp_XY& point2D,
1279 const gp_XY* segEnds,
1280 const int index0 = 0,
1281 const int posToFindOut = POS_ALL)
1283 const gp_XY& p1 = segEnds[ index0 ];
1284 const gp_XY& p2 = segEnds[ index0+1 ];
1285 const gp_XY grad = p2 - p1;
1287 if ( posToFindOut & POS_VERTEX )
1289 // check if the point2D is at "vertex 1" zone
1290 gp_XY pp1[2] = { p1, gp_XY( p1.X() - grad.Y(),
1291 p1.Y() + grad.X() ) };
1292 if ( getPointPosition( point2D, pp1, 0, POS_LEFT|POS_RIGHT )._name == POS_LEFT )
1293 return PointPos( POS_VERTEX, index0 );
1295 // check if the point2D is at "vertex 2" zone
1296 gp_XY pp2[2] = { p2, gp_XY( p2.X() - grad.Y(),
1297 p2.Y() + grad.X() ) };
1298 if ( getPointPosition( point2D, pp2, 0, POS_LEFT|POS_RIGHT )._name == POS_RIGHT )
1299 return PointPos( POS_VERTEX, index0 + 1);
1301 double edgeEquation =
1302 ( point2D.X() - p1.X() ) * grad.Y() - ( point2D.Y() - p1.Y() ) * grad.X();
1303 return PointPos( edgeEquation < 0 ? POS_LEFT : POS_RIGHT, index0 );
1307 //=======================================================================
1309 * \brief Return minimal distance from a point to an element
1311 * Currently we ignore non-planarity and 2nd order of face
1313 //=======================================================================
1315 double SMESH_MeshAlgos::GetDistance( const SMDS_MeshElement* elem,
1316 const gp_Pnt& point )
1318 switch ( elem->GetType() )
1320 case SMDSAbs_Volume:
1321 return GetDistance( dynamic_cast<const SMDS_MeshVolume*>( elem ), point);
1323 return GetDistance( dynamic_cast<const SMDS_MeshFace*>( elem ), point);
1325 return GetDistance( dynamic_cast<const SMDS_MeshEdge*>( elem ), point);
1327 return point.Distance( SMESH_TNodeXYZ( elem ));
1332 //=======================================================================
1334 * \brief Return minimal distance from a point to a face
1336 * Currently we ignore non-planarity and 2nd order of face
1338 //=======================================================================
1340 double SMESH_MeshAlgos::GetDistance( const SMDS_MeshFace* face,
1341 const gp_Pnt& point )
1343 double badDistance = -1;
1344 if ( !face ) return badDistance;
1346 // coordinates of nodes (medium nodes, if any, ignored)
1347 typedef SMDS_StdIterator< SMESH_TNodeXYZ, SMDS_ElemIteratorPtr > TXyzIterator;
1348 vector<gp_XYZ> xyz( TXyzIterator( face->nodesIterator()), TXyzIterator() );
1349 xyz.resize( face->NbCornerNodes()+1 );
1351 // transformation to get xyz[0] lies on the origin, xyz[1] lies on the Z axis,
1352 // and xyz[2] lies in the XZ plane. This is to pass to 2D space on XZ plane.
1354 gp_Vec OZ ( xyz[0], xyz[1] );
1355 gp_Vec OX ( xyz[0], xyz[2] );
1356 if ( OZ.Magnitude() < std::numeric_limits<double>::min() )
1358 if ( xyz.size() < 4 ) return badDistance;
1359 OZ = gp_Vec ( xyz[0], xyz[2] );
1360 OX = gp_Vec ( xyz[0], xyz[3] );
1364 tgtCS = gp_Ax3( xyz[0], OZ, OX );
1366 catch ( Standard_Failure ) {
1369 trsf.SetTransformation( tgtCS );
1371 // move all the nodes to 2D
1372 vector<gp_XY> xy( xyz.size() );
1373 for ( size_t i = 0;i < xyz.size()-1; ++i )
1375 gp_XYZ p3d = xyz[i];
1376 trsf.Transforms( p3d );
1377 xy[i].SetCoord( p3d.X(), p3d.Z() );
1379 xyz.back() = xyz.front();
1380 xy.back() = xy.front();
1382 // // move the point in 2D
1383 gp_XYZ tmpPnt = point.XYZ();
1384 trsf.Transforms( tmpPnt );
1385 gp_XY point2D( tmpPnt.X(), tmpPnt.Z() );
1387 // loop on segments of the face to analyze point position ralative to the face
1388 set< PointPos > pntPosSet;
1389 for ( size_t i = 1; i < xy.size(); ++i )
1391 PointPos pos = getPointPosition( point2D, &xy[0], i-1 );
1392 pntPosSet.insert( pos );
1396 PointPos pos = *pntPosSet.begin();
1397 // cout << "Face " << face->GetID() << " DIST: ";
1398 switch ( pos._name )
1401 // point is most close to a segment
1402 gp_Vec p0p1( point, xyz[ pos._index ] );
1403 gp_Vec p1p2( xyz[ pos._index ], xyz[ pos._index+1 ]); // segment vector
1405 double projDist = p0p1 * p1p2; // distance projected to the segment
1406 gp_Vec projVec = p1p2 * projDist;
1407 gp_Vec distVec = p0p1 - projVec;
1408 // cout << distVec.Magnitude() << ", SEG " << face->GetNode(pos._index)->GetID()
1409 // << " - " << face->GetNodeWrap(pos._index+1)->GetID() << endl;
1410 return distVec.Magnitude();
1413 // point is inside the face
1414 double distToFacePlane = tmpPnt.Y();
1415 // cout << distToFacePlane << ", INSIDE " << endl;
1416 return Abs( distToFacePlane );
1419 // point is most close to a node
1420 gp_Vec distVec( point, xyz[ pos._index ]);
1421 // cout << distVec.Magnitude() << " VERTEX " << face->GetNode(pos._index)->GetID() << endl;
1422 return distVec.Magnitude();
1428 //=======================================================================
1430 * \brief Return minimal distance from a point to an edge
1432 //=======================================================================
1434 double SMESH_MeshAlgos::GetDistance( const SMDS_MeshEdge* edge, const gp_Pnt& point )
1436 throw SALOME_Exception(LOCALIZED("not implemented so far"));
1439 //=======================================================================
1441 * \brief Return minimal distance from a point to a volume
1443 * Currently we ignore non-planarity and 2nd order
1445 //=======================================================================
1447 double SMESH_MeshAlgos::GetDistance( const SMDS_MeshVolume* volume, const gp_Pnt& point )
1449 SMDS_VolumeTool vTool( volume );
1450 vTool.SetExternalNormal();
1451 const int iQ = volume->IsQuadratic() ? 2 : 1;
1454 double minDist = 1e100, dist;
1455 for ( int iF = 0; iF < vTool.NbFaces(); ++iF )
1457 // skip a facet with normal not "looking at" the point
1458 if ( !vTool.GetFaceNormal( iF, n[0], n[1], n[2] ) ||
1459 !vTool.GetFaceBaryCenter( iF, bc[0], bc[1], bc[2] ))
1461 gp_XYZ bcp = point.XYZ() - gp_XYZ( bc[0], bc[1], bc[2] );
1462 if ( gp_XYZ( n[0], n[1], n[2] ) * bcp < 1e-6 )
1465 // find distance to a facet
1466 const SMDS_MeshNode** nodes = vTool.GetFaceNodes( iF );
1467 switch ( vTool.NbFaceNodes( iF ) / iQ ) {
1470 SMDS_FaceOfNodes tmpFace( nodes[0], nodes[ 1*iQ ], nodes[ 2*iQ ] );
1471 dist = GetDistance( &tmpFace, point );
1476 SMDS_FaceOfNodes tmpFace( nodes[0], nodes[ 1*iQ ], nodes[ 2*iQ ], nodes[ 3*iQ ]);
1477 dist = GetDistance( &tmpFace, point );
1481 vector<const SMDS_MeshNode *> nvec( nodes, nodes + vTool.NbFaceNodes( iF ));
1482 SMDS_PolygonalFaceOfNodes tmpFace( nvec );
1483 dist = GetDistance( &tmpFace, point );
1485 minDist = Min( minDist, dist );
1490 //================================================================================
1492 * \brief Returns barycentric coordinates of a point within a triangle.
1493 * A not returned bc2 = 1. - bc0 - bc1.
1494 * The point lies within the triangle if ( bc0 >= 0 && bc1 >= 0 && bc0+bc1 <= 1 )
1496 //================================================================================
1498 void SMESH_MeshAlgos::GetBarycentricCoords( const gp_XY& p,
1505 const double // matrix 2x2
1506 T11 = t0.X()-t2.X(), T12 = t1.X()-t2.X(),
1507 T21 = t0.Y()-t2.Y(), T22 = t1.Y()-t2.Y();
1508 const double Tdet = T11*T22 - T12*T21; // matrix determinant
1509 if ( Abs( Tdet ) < std::numeric_limits<double>::min() )
1515 const double t11 = T22, t12 = -T12, t21 = -T21, t22 = T11;
1517 const double r11 = p.X()-t2.X(), r12 = p.Y()-t2.Y();
1518 // barycentric coordinates: mutiply matrix by vector
1519 bc0 = (t11 * r11 + t12 * r12)/Tdet;
1520 bc1 = (t21 * r11 + t22 * r12)/Tdet;
1523 //=======================================================================
1524 //function : FindFaceInSet
1525 //purpose : Return a face having linked nodes n1 and n2 and which is
1526 // - not in avoidSet,
1527 // - in elemSet provided that !elemSet.empty()
1528 // i1 and i2 optionally returns indices of n1 and n2
1529 //=======================================================================
1531 const SMDS_MeshElement*
1532 SMESH_MeshAlgos::FindFaceInSet(const SMDS_MeshNode* n1,
1533 const SMDS_MeshNode* n2,
1534 const TIDSortedElemSet& elemSet,
1535 const TIDSortedElemSet& avoidSet,
1541 const SMDS_MeshElement* face = 0;
1543 SMDS_ElemIteratorPtr invElemIt = n1->GetInverseElementIterator(SMDSAbs_Face);
1544 while ( invElemIt->more() && !face ) // loop on inverse faces of n1
1546 const SMDS_MeshElement* elem = invElemIt->next();
1547 if (avoidSet.count( elem ))
1549 if ( !elemSet.empty() && !elemSet.count( elem ))
1552 i1 = elem->GetNodeIndex( n1 );
1553 // find a n2 linked to n1
1554 int nbN = elem->IsQuadratic() ? elem->NbNodes()/2 : elem->NbNodes();
1555 for ( int di = -1; di < 2 && !face; di += 2 )
1557 i2 = (i1+di+nbN) % nbN;
1558 if ( elem->GetNode( i2 ) == n2 )
1561 if ( !face && elem->IsQuadratic())
1563 // analysis for quadratic elements using all nodes
1564 SMDS_ElemIteratorPtr anIter = elem->interlacedNodesElemIterator();
1565 const SMDS_MeshNode* prevN = static_cast<const SMDS_MeshNode*>( anIter->next() );
1566 for ( i1 = -1, i2 = 0; anIter->more() && !face; i1++, i2++ )
1568 const SMDS_MeshNode* n = static_cast<const SMDS_MeshNode*>( anIter->next() );
1569 if ( n1 == prevN && n2 == n )
1573 else if ( n2 == prevN && n1 == n )
1575 face = elem; swap( i1, i2 );
1581 if ( n1ind ) *n1ind = i1;
1582 if ( n2ind ) *n2ind = i2;
1586 //================================================================================
1588 * \brief Calculate normal of a mesh face
1590 //================================================================================
1592 bool SMESH_MeshAlgos::FaceNormal(const SMDS_MeshElement* F, gp_XYZ& normal, bool normalized)
1594 if ( !F || F->GetType() != SMDSAbs_Face )
1597 normal.SetCoord(0,0,0);
1598 int nbNodes = F->NbCornerNodes();
1599 for ( int i = 0; i < nbNodes-2; ++i )
1602 for ( int n = 0; n < 3; ++n )
1604 const SMDS_MeshNode* node = F->GetNode( i + n );
1605 p[n].SetCoord( node->X(), node->Y(), node->Z() );
1607 normal += ( p[2] - p[1] ) ^ ( p[0] - p[1] );
1609 double size2 = normal.SquareModulus();
1610 bool ok = ( size2 > numeric_limits<double>::min() * numeric_limits<double>::min());
1611 if ( normalized && ok )
1612 normal /= sqrt( size2 );
1617 //=======================================================================
1618 //function : GetCommonNodes
1619 //purpose : Return nodes common to two elements
1620 //=======================================================================
1622 vector< const SMDS_MeshNode*> SMESH_MeshAlgos::GetCommonNodes(const SMDS_MeshElement* e1,
1623 const SMDS_MeshElement* e2)
1625 vector< const SMDS_MeshNode*> common;
1626 for ( int i = 0 ; i < e1->NbNodes(); ++i )
1627 if ( e2->GetNodeIndex( e1->GetNode( i )) >= 0 )
1628 common.push_back( e1->GetNode( i ));
1632 //=======================================================================
1634 * \brief Return SMESH_NodeSearcher
1636 //=======================================================================
1638 SMESH_NodeSearcher* SMESH_MeshAlgos::GetNodeSearcher(SMDS_Mesh& mesh)
1640 return new SMESH_NodeSearcherImpl( &mesh );
1643 //=======================================================================
1645 * \brief Return SMESH_ElementSearcher
1647 //=======================================================================
1649 SMESH_ElementSearcher* SMESH_MeshAlgos::GetElementSearcher(SMDS_Mesh& mesh,
1652 return new SMESH_ElementSearcherImpl( mesh, tolerance );
1655 //=======================================================================
1657 * \brief Return SMESH_ElementSearcher acting on a sub-set of elements
1659 //=======================================================================
1661 SMESH_ElementSearcher* SMESH_MeshAlgos::GetElementSearcher(SMDS_Mesh& mesh,
1662 SMDS_ElemIteratorPtr elemIt,
1665 return new SMESH_ElementSearcherImpl( mesh, tolerance, elemIt );