+//================================================================================
+/*!
+ * \brief Return true if an edge can be considered straight
+ */
+//================================================================================
+
+bool SMESH_Algo::isStraight( const TopoDS_Edge & E,
+ const bool degenResult)
+{
+ {
+ double f,l;
+ if ( BRep_Tool::Curve( E, f, l ).IsNull())
+ return degenResult;
+ }
+ BRepAdaptor_Curve curve( E );
+ switch( curve.GetType() )
+ {
+ case GeomAbs_Line:
+ return true;
+ case GeomAbs_Circle:
+ case GeomAbs_Ellipse:
+ case GeomAbs_Hyperbola:
+ case GeomAbs_Parabola:
+ return false;
+ // case GeomAbs_BezierCurve:
+ // case GeomAbs_BSplineCurve:
+ // case GeomAbs_OtherCurve:
+ default:;
+ }
+ const double f = curve.FirstParameter();
+ const double l = curve.LastParameter();
+ const gp_Pnt pf = curve.Value( f );
+ const gp_Pnt pl = curve.Value( l );
+ const gp_Vec v1( pf, pl );
+ const double v1Len = v1.Magnitude();
+ if ( v1Len < std::numeric_limits< double >::min() )
+ return false; // E seems closed
+ const double tol = Min( 10 * curve.Tolerance(), v1Len * 1e-2 );
+ const int nbSamples = 7;
+ for ( int i = 0; i < nbSamples; ++i )
+ {
+ const double r = ( i + 1 ) / nbSamples;
+ const gp_Pnt pi = curve.Value( f * r + l * ( 1 - r ));
+ const gp_Vec vi( pf, pi );
+ const double h = 0.5 * v1.Crossed( vi ).Magnitude() / v1Len;
+ if ( h > tol )
+ return false;
+ }
+ return true;
+}
+
