+// Copyright (C) 2007-2016 CEA/DEN, EDF R&D, OPEN CASCADE
+//
+// Copyright (C) 2003-2007 OPEN CASCADE, EADS/CCR, LIP6, CEA/DEN,
+// CEDRAT, EDF R&D, LEG, PRINCIPIA R&D, BUREAU VERITAS
+//
+// This library is free software; you can redistribute it and/or
+// modify it under the terms of the GNU Lesser General Public
+// License as published by the Free Software Foundation; either
+// version 2.1 of the License, or (at your option) any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+// Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License along with this library; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+//
+// See http://www.salome-platform.org/ or email : webmaster.salome@opencascade.com
+//
+// File : SMESH_Delaunay.cxx
+// Created : Wed Apr 19 15:41:15 2017
+// Author : Edward AGAPOV (eap)
+
+#include "SMESH_Delaunay.hxx"
+#include "SMESH_MeshAlgos.hxx"
+
+#include <BRepAdaptor_Surface.hxx>
+#include <BRepMesh_Delaun.hxx>
+
+//================================================================================
+/*!
+ * \brief Construct a Delaunay triangulation of given boundary nodes
+ * \param [in] boundaryNodes - vector of nodes of a wire
+ * \param [in] face - the face
+ * \param [in] faceID - the face ID
+ * \param [in] nbNodesToVisit - nb of non-marked nodes on the face
+ */
+//================================================================================
+
+SMESH_Delaunay::SMESH_Delaunay(const std::vector< const UVPtStructVec* > & boundaryNodes,
+ const TopoDS_Face& face,
+ const int faceID)
+ : _face( face ), _faceID( faceID ), _scale( 1., 1. )
+{
+ // compute _scale
+ BRepAdaptor_Surface surf( face );
+ if ( surf.GetType() != GeomAbs_Plane )
+ {
+ const int nbDiv = 100;
+ const double uRange = surf.LastUParameter() - surf.FirstUParameter();
+ const double vRange = surf.LastVParameter() - surf.FirstVParameter();
+ const double dU = uRange / nbDiv;
+ const double dV = vRange / nbDiv;
+ double u = surf.FirstUParameter(), v = surf.FirstVParameter();
+ gp_Pnt p0U = surf.Value( u, v ), p0V = p0U;
+ double lenU = 0, lenV = 0;
+ for ( ; u < surf.LastUParameter(); u += dU, v += dV )
+ {
+ gp_Pnt p1U = surf.Value( u, surf.FirstVParameter() );
+ lenU += p1U.Distance( p0U );
+ p0U = p1U;
+ gp_Pnt p1V = surf.Value( surf.FirstUParameter(), v );
+ lenV += p1V.Distance( p0V );
+ p0V = p1V;
+ }
+ _scale.SetCoord( lenU / uRange, lenV / vRange );
+ }
+
+ // count boundary points
+ int iP = 1, nbP = 0;
+ for ( size_t iW = 0; iW < boundaryNodes.size(); ++iW ) // loop on wires
+ {
+ nbP += boundaryNodes[iW]->size();
+ if ( boundaryNodes[iW]->front().node == boundaryNodes[iW]->back().node )
+ --nbP; // 1st and last points coincide
+ }
+ _bndNodes.resize( nbP );
+
+ // fill boundary points
+ BRepMesh::Array1OfVertexOfDelaun bndVert( 1, 1 + nbP );
+ BRepMesh_Vertex v( 0, 0, BRepMesh_Frontier );
+ for ( size_t iW = 0; iW < boundaryNodes.size(); ++iW )
+ {
+ const UVPtStructVec& bndPnt = *boundaryNodes[iW];
+ int i = 0, nb = bndPnt.size();
+ if ( bndPnt[0].node == bndPnt.back().node )
+ --nb;
+ for ( ; i < nb; ++i, ++iP )
+ {
+ _bndNodes[ iP-1 ] = bndPnt[i].node;
+ bndPnt[i].node->setIsMarked( true );
+
+ v.ChangeCoord() = bndPnt[i].UV().Multiplied( _scale );
+ bndVert( iP ) = v;
+ }
+ }
+
+ // triangulate the srcFace in 2D
+ BRepMesh_Delaun Delaunay( bndVert );
+ _triaDS = Delaunay.Result();
+}
+
+//================================================================================
+/*!
+ * \brief Prepare to the exploration of nodes
+ */
+//================================================================================
+
+void SMESH_Delaunay::InitTraversal(const int nbNodesToVisit)
+{
+ _nbNodesToVisit = (size_t) nbNodesToVisit;
+ _nbVisitedNodes = _iBndNode = 0;
+ _noTriQueue.clear();
+}
+
+//================================================================================
+/*!
+ * \brief Return a node with its Barycentric Coordinates within the triangle
+ * defined by its node indices (zero based)
+ * \param [out] bc - Barycentric Coordinates of the returned node
+ * \param [out] triaNodes - indices of triangle nodes
+ * \return const SMDS_MeshNode* - the next node or NULL
+ */
+//================================================================================
+
+const SMDS_MeshNode* SMESH_Delaunay::NextNode( double bc[3], int triaNodes[3] )
+{
+ while ( _nbVisitedNodes < _nbNodesToVisit )
+ {
+ while ( !_noTriQueue.empty() )
+ {
+ const SMDS_MeshNode* node = _noTriQueue.front().first;
+ const BRepMesh_Triangle* tria = _noTriQueue.front().second;
+ _noTriQueue.pop_front();
+ if ( node->isMarked() )
+ continue;
+ ++_nbVisitedNodes;
+ node->setIsMarked( true );
+
+ // find a Delaunay triangle containing the src node
+ gp_XY uv = getNodeUV( _face, node );
+ tria = FindTriangle( uv, tria, bc, triaNodes );
+ if ( tria )
+ {
+ addCloseNodes( node, tria, _faceID, _noTriQueue );
+ return node;
+ }
+ }
+ for ( ; _iBndNode < _bndNodes.size() && _noTriQueue.empty(); ++_iBndNode )
+ {
+ if ( const BRepMesh_Triangle* tria = GetTriangleNear( _iBndNode ))
+ addCloseNodes( _bndNodes[ _iBndNode ], tria, _faceID, _noTriQueue );
+ }
+ if ( _noTriQueue.empty() )
+ break;
+ }
+
+ // if ( _nbVisitedNodes < _nbNodesToVisit )
+ // _nbVisitedNodes = std::numeric_limits<int>::max();
+ return NULL;
+}
+
+//================================================================================
+/*!
+ * \brief Find a Delaunay triangle containing a given 2D point and return
+ * barycentric coordinates within the found triangle
+ */
+//================================================================================
+
+const BRepMesh_Triangle* SMESH_Delaunay::FindTriangle( const gp_XY& UV,
+ const BRepMesh_Triangle* tria,
+ double bc[3],
+ int triaNodes[3] )
+{
+ int nodeIDs[3];
+ gp_XY nodeUVs[3];
+ int linkIDs[3];
+ Standard_Boolean ori[3];
+
+ gp_XY uv = UV.Multiplied( _scale );
+
+ while ( tria )
+ {
+ // check if the uv is in tria
+
+ _triaDS->ElementNodes( *tria, nodeIDs );
+ nodeUVs[0] = _triaDS->GetNode( nodeIDs[0] ).Coord();
+ nodeUVs[1] = _triaDS->GetNode( nodeIDs[1] ).Coord();
+ nodeUVs[2] = _triaDS->GetNode( nodeIDs[2] ).Coord();
+
+ SMESH_MeshAlgos::GetBarycentricCoords( uv,
+ nodeUVs[0], nodeUVs[1], nodeUVs[2],
+ bc[0], bc[1] );
+ if ( bc[0] >= 0 && bc[1] >= 0 && bc[0] + bc[1] <= 1 )
+ {
+ bc[2] = 1 - bc[0] - bc[1];
+ triaNodes[0] = nodeIDs[0] - 1;
+ triaNodes[1] = nodeIDs[1] - 1;
+ triaNodes[2] = nodeIDs[2] - 1;
+ return tria;
+ }
+
+ // look for a neighbor triangle, which is adjacent to a link intersected
+ // by a segment( triangle center -> uv )
+
+ gp_XY gc = ( nodeUVs[0] + nodeUVs[1] + nodeUVs[2] ) / 3.;
+ gp_XY seg = uv - gc;
+
+ tria->Edges( linkIDs, ori );
+ int triaID = _triaDS->IndexOf( *tria );
+ tria = 0;
+
+ for ( int i = 0; i < 3; ++i )
+ {
+ const BRepMesh_PairOfIndex & triIDs = _triaDS->ElementsConnectedTo( linkIDs[i] );
+ if ( triIDs.Extent() < 2 )
+ continue; // no neighbor triangle
+
+ // check if a link intersects gc2uv
+ const BRepMesh_Edge & link = _triaDS->GetLink( linkIDs[i] );
+ const BRepMesh_Vertex & n1 = _triaDS->GetNode( link.FirstNode() );
+ const BRepMesh_Vertex & n2 = _triaDS->GetNode( link.LastNode() );
+ gp_XY uv1 = n1.Coord();
+ gp_XY lin = n2.Coord() - uv1; // link direction
+
+ double crossSegLin = seg ^ lin;
+ if ( Abs( crossSegLin ) < std::numeric_limits<double>::min() )
+ continue; // parallel
+
+ double uSeg = ( uv1 - gc ) ^ lin / crossSegLin;
+ if ( 0. <= uSeg && uSeg <= 1. )
+ {
+ tria = & _triaDS->GetElement( triIDs.Index( 1 + ( triIDs.Index(1) == triaID )));
+ break;
+ }
+ }
+ }
+ return tria;
+}
+
+//================================================================================
+/*!
+ * \brief Return a triangle sharing a given boundary node
+ * \param [in] iBndNode - index of the boundary node
+ * \return const BRepMesh_Triangle* - a found triangle
+ */
+//================================================================================
+
+const BRepMesh_Triangle* SMESH_Delaunay::GetTriangleNear( int iBndNode )
+{
+ const BRepMesh::ListOfInteger & linkIds = _triaDS->LinksConnectedTo( iBndNode + 1 );
+ const BRepMesh_PairOfIndex & triaIds = _triaDS->ElementsConnectedTo( linkIds.First() );
+ const BRepMesh_Triangle& tria = _triaDS->GetElement( triaIds.Index(1) );
+ return &tria;
+}
+
+//================================================================================
+/*!
+ * \brief Return UV of the i-th source boundary node (zero based)
+ */
+//================================================================================
+
+gp_XY SMESH_Delaunay::GetBndUV(const int iNode) const
+{
+ return _triaDS->GetNode( iNode+1 ).Coord();
+}
+
+//================================================================================
+/*!
+ * \brief Add non-marked nodes surrounding a given one to a queue
+ */
+//================================================================================
+
+void SMESH_Delaunay::addCloseNodes( const SMDS_MeshNode* node,
+ const BRepMesh_Triangle* tria,
+ const int faceID,
+ TNodeTriaList & _noTriQueue )
+{
+ // find in-FACE nodes
+ SMDS_ElemIteratorPtr elems = node->GetInverseElementIterator(SMDSAbs_Face);
+ while ( elems->more() )
+ {
+ const SMDS_MeshElement* elem = elems->next();
+ if ( elem->getshapeId() == faceID )
+ {
+ for ( int i = 0, nb = elem->NbNodes(); i < nb; ++i )
+ {
+ const SMDS_MeshNode* n = elem->GetNode( i );
+ if ( !n->isMarked() /*&& n->getshapeId() == faceID*/ )
+ _noTriQueue.push_back( std::make_pair( n, tria ));
+ }
+ }
+ }
+}