+ inline double segLength(double S0, double edgeLen, double minLen )
+ {
+ // PAL10237
+ // S = S0 * f(L/Lmin) where
+ // f(x) = 1 + (7 * 2/Pi * atan(x/5))
+ // =>
+ // S = S0 * ( 1 + 14/PI * atan( L / ( 5 * Lmin )))
+ //
+ // return S0 * ( 1. + a14divPI * atan( edgeLen / ( 5 * minLen )));
+
+ // The above formular gives too short segments when Lmax/Lmin is too high
+ // because by this formular the largest segment is only 8 times longer than the
+ // shortest one ( 2/Pi * atan(x/5) varies within [0,1] ). So a new formular is:
+ //
+ // f(x) = 1 + (x/7 * 2/Pi * atan(x/5))
+ // =>
+ // S = S0 * ( 1 + 2/7/PI * L/Lmin * atan( 5 * L/Lmin ))
+ //
+ const double Lratio = edgeLen / minLen;
+ return S0 * ( 1. + a2div7divPI * Lratio * atan( 5 * Lratio ));
+ }
+#endif
+ //================================================================================
+ /*!
+ * \brief Compute segment length for all edges
+ * \param theMesh - The mesh
+ * \param theTShapeToLengthMap - The map of edge to segment length
+ */
+ //================================================================================
+
+ void computeLengths( SMESHDS_Mesh* aMesh,
+ map<const TopoDS_TShape*, double> & theTShapeToLengthMap,
+ double & theS0,
+ double & theMinLen)
+ {
+ theTShapeToLengthMap.clear();
+
+ TopoDS_Shape aMainShape = aMesh->ShapeToMesh();
+
+ // Find length of longest and shortest edge
+ double Lmin = DBL_MAX, Lmax = -DBL_MAX;
+ TopTools_IndexedMapOfShape edgeMap;
+ TopExp::MapShapes( aMainShape, TopAbs_EDGE, edgeMap);
+ for ( int i = 1; i <= edgeMap.Extent(); ++i )
+ {
+ TopoDS_Edge edge = TopoDS::Edge( edgeMap(i) );
+ //if ( BRep_Tool::Degenerated( edge )) continue;
+
+ Standard_Real L = SMESH_Algo::EdgeLength( edge );
+ if ( L < DBL_MIN ) continue;
+
+ if ( L > Lmax ) Lmax = L;
+ if ( L < Lmin ) Lmin = L;
+
+ // remember i-th edge length
+ theTShapeToLengthMap.insert( make_pair( getTShape( edge ), L ));
+ }
+
+ // Compute S0 - minimal segement length, is computed by the shortest EDGE
+
+ /* image attached to PAL10237
+
+ NbSeg (on the shortest EDGE)
+ ^
+ |
+ 10|\
+ | \
+ | \
+ | \
+ 5| --------
+ |
+ +------------>
+ 1 10 Lmax/Lmin
+ */
+ const int NbSegMin = 5, NbSegMax = 10; // on axis NbSeg
+ const double Lrat1 = 1., Lrat2 = 10.; // on axis Lmax/Lmin
+
+ double Lratio = Lmax/Lmin;
+ double NbSeg = NbSegMin;
+ if ( Lratio < Lrat2 )
+ NbSeg += ( Lrat2 - Lratio ) / ( Lrat2 - Lrat1 ) * ( NbSegMax - NbSegMin );
+
+ double S0 = Lmin / (int) NbSeg;
+ MESSAGE( "S0 = " << S0 << ", Lmin = " << Lmin << ", Nbseg = " << (int) NbSeg);
+
+ // Compute segments length for all edges
+
+ map<const TopoDS_TShape*, double>::iterator tshape_length = theTShapeToLengthMap.begin();
+ for ( ; tshape_length != theTShapeToLengthMap.end(); ++tshape_length )
+ {
+ double & L = tshape_length->second;
+ L = segLength( S0, L, Lmin );
+ }
+ theS0 = S0;
+ theMinLen = Lmin;
+ }
+}