+ }
+ else if(aType == VECTOR_TANGENT_CURVE_PAR) {
+ Handle(GEOM_Function) aRefCurve = aPI.GetCurve();
+ TopoDS_Shape aRefShape = aRefCurve->GetValue();
+ if (aRefShape.ShapeType() != TopAbs_EDGE) {
+ Standard_TypeMismatch::Raise
+ ("Tangent On Curve creation aborted : curve shape is not an edge");
+ }
+ Standard_Real aFParam =0., aLParam =0., aParam =0.;
+ Handle(Geom_Curve) aCurve = BRep_Tool::Curve(TopoDS::Edge(aRefShape), aFParam, aLParam);
+ if(aCurve.IsNull()) {
+ Standard_TypeMismatch::Raise
+ ("Tangent On Curve creation aborted : curve is null");
+ }
+
+ aParam = aFParam + (aLParam - aFParam) * aPI.GetParameter();
+ gp_Pnt aPoint1,aPoint2;
+ gp_Vec aVec;
+ aCurve->D1(aParam,aPoint1,aVec);
+ if(aVec.Magnitude() < gp::Resolution())
+ Standard_TypeMismatch::Raise
+ ("Tangent On Curve creation aborted : invalid value of tangent");
+ aPoint2.SetXYZ(aPoint1.XYZ() + aVec.XYZ());
+ BRepBuilderAPI_MakeEdge aBuilder(aPoint1,aPoint2);
+ if(aBuilder.IsDone())
+ aShape = aBuilder.Shape();