PyObject* MatrixPy::scale(PyObject * args)
{
    double x,y,z;
    Base::Vector3d vec;
    PyObject *pcVecObj;

    if (PyArg_ParseTuple(args, "ddd", &x,&y,&z)) {   // convert args: Python->C
        vec.x = x;
        vec.y = y;
        vec.z = z;
    }
    else if (PyArg_ParseTuple(args, "O!:three floats or a vector is needed", 
        &PyTuple_Type, &pcVecObj)) {
        vec = getVectorFromTuple<double>(pcVecObj);
        // clears the error from the first PyArg_ParseTuple()6
        PyErr_Clear();
    }
    else if (PyArg_ParseTuple(args, "O!:three floats or a vector is needed", &(Base::VectorPy::Type), &pcVecObj)) {
        // convert args: Python->C
        Base::VectorPy  *pcObject = static_cast<Base::VectorPy*>(pcVecObj);
        Base::Vector3d* val = pcObject->getVectorPtr();
        vec.Set(val->x,val->y,val->z);
        // clears the error from the first PyArg_ParseTuple()6
        PyErr_Clear();
    }
    else
        return NULL;

    PY_TRY {
        getMatrixPtr()->scale(vec);
    }
    PY_CATCH;

    Py_Return;
}

/// utility non-class member functions
//! gets a coordinate system that matches view system used in 3D with +Z up (or +Y up if neccessary)
//! used for individual views, but not secondary views in projection groups
gp_Ax2 TechDrawGeometry::getViewAxis(const Base::Vector3d origin,
                                     const Base::Vector3d& direction,
                                     const bool flip)
{
    gp_Pnt inputCenter(origin.x,origin.y,origin.z);
    Base::Vector3d stdZ(0.0,0.0,1.0);
    Base::Vector3d flipDirection(direction.x,-direction.y,direction.z);
    if (!flip) {
        flipDirection = Base::Vector3d(direction.x,direction.y,direction.z);
    }
    Base::Vector3d cross = flipDirection;
    //special cases
    if (flipDirection == stdZ) {
        cross = Base::Vector3d(1.0,0.0,0.0);
    } else if (flipDirection == (stdZ * -1.0)) {
        cross = Base::Vector3d(1.0,0.0,0.0);
    } else {
        cross.Normalize();
        cross = cross.Cross(stdZ);
    }
    gp_Ax2 viewAxis;
    viewAxis = gp_Ax2(inputCenter,
                      gp_Dir(flipDirection.x, flipDirection.y, flipDirection.z),
//                      gp_Dir(1.0, 1.0, 0.0));
                      gp_Dir(cross.x, cross.y, cross.z));
    return viewAxis;
}

PyObject* MatrixPy::transform(PyObject * args)
{
    Base::Vector3d vec;
    Matrix4D mat;
    PyObject *pcVecObj,*pcMatObj;

    if (PyArg_ParseTuple(args, "O!O!: a transform point (Vector) and a transform matrix (Matrix) is needed",
        &(Base::VectorPy::Type), &pcVecObj, &(MatrixPy::Type), &pcMatObj) ) {   // convert args: Python->C
        Base::VectorPy  *pcObject = static_cast<Base::VectorPy*>(pcVecObj);
        Base::Vector3d* val = pcObject->getVectorPtr();
        vec.Set(val->x,val->y,val->z);
        mat = *(static_cast<MatrixPy*>(pcMatObj)->getMatrixPtr());
        // clears the error from the first PyArg_ParseTuple()6
        PyErr_Clear();
    }
    else
        return NULL;                                 // NULL triggers exception

    PY_TRY {
        getMatrixPtr()->transform(vec,mat);
    }
    PY_CATCH;

    Py_Return;
}

void TrajectoryVisualization::setColor(const base::Vector3d& color)
{
    { boost::mutex::scoped_lock lockit(this->updateMutex);
        this->color = osg::Vec4(color.x(), color.y(), color.z(), 1.0); }
    emit propertyChanged("Color");
    setDirty();
}

Extrusion::ExtrusionParameters Extrusion::computeFinalParameters()
{
    Extrusion::ExtrusionParameters result;
    Base::Vector3d dir;
    switch(this->DirMode.getValue()){
        case dmCustom:
            dir = this->Dir.getValue();
        break;
        case dmEdge:{
            bool fetched;
            Base::Vector3d base;
            fetched = fetchAxisLink(this->DirLink, base, dir);
            if (! fetched)
                throw Base::Exception("DirMode is set to use edge, but no edge is linked.");
            this->Dir.setValue(dir);
        }break;
        case dmNormal:
            dir = calculateShapeNormal(this->Base);
            this->Dir.setValue(dir);
        break;
        default:
            throw Base::ValueError("Unexpected enum value");
    }
    if(dir.Length() < Precision::Confusion())
        throw Base::ValueError("Direction is zero-length");
    result.dir = gp_Dir(dir.x, dir.y, dir.z);
    if (this->Reversed.getValue())
        result.dir.Reverse();

    result.lengthFwd = this->LengthFwd.getValue();
    result.lengthRev = this->LengthRev.getValue();
    if(fabs(result.lengthFwd) < Precision::Confusion()
            && fabs(result.lengthRev) < Precision::Confusion() ){
        result.lengthFwd = dir.Length();
    }

    if (this->Symmetric.getValue()){
        result.lengthRev = result.lengthFwd * 0.5;
        result.lengthFwd = result.lengthFwd * 0.5;
    }

    if (fabs(result.lengthFwd + result.lengthRev) < Precision::Confusion())
        throw Base::ValueError("Total length of extrusion is zero.");

    result.solid = this->Solid.getValue();

    result.taperAngleFwd = this->TaperAngle.getValue() * M_PI / 180.0;
    if (fabs(result.taperAngleFwd) > M_PI * 0.5 - Precision::Angular() )
        throw Base::ValueError("Magnitude of taper angle matches or exceeds 90 degrees. That is too much.");
    result.taperAngleRev = this->TaperAngleRev.getValue() * M_PI / 180.0;
    if (fabs(result.taperAngleRev) > M_PI * 0.5 - Precision::Angular() )
        throw Base::ValueError("Magnitude of taper angle matches or exceeds 90 degrees. That is too much.");

    result.faceMakerClass = this->FaceMakerClass.getValue();

    return result;
}

Base::Vector3d MeshObject::getPointNormal(unsigned long index) const
{
    std::vector<Base::Vector3f> temp = _kernel.CalcVertexNormals();
    Base::Vector3d normal = transformToOutside(temp[index]);

    // the normal is a vector, hence we must not apply the translation part
    // of the transformation to the vector
    normal.x -= _Mtrx[0][3];
    normal.y -= _Mtrx[1][3];
    normal.z -= _Mtrx[2][3];
    normal.Normalize();
    return normal;
}

void TrajectoryVisualization::updateDataIntern( const base::Vector3d& data )
{
    if(doClear)
    {
        points.clear();
        doClear = false;
    }
    Point p;
    p.point = osg::Vec3(data.x(), data.y(), data.z());
    p.color = color;
    points.push_back(p);
    while(points.size() > max_number_of_points)
        points.pop_front();
}

base::Vector3d SplineBase::poseError(base::Vector3d _position, double _heading, double _guess)
{
    double param = findOneClosestPoint(_position.data(), _guess, getGeometricResolution());

    // Returns the error [distance error, orientation error, parameter] 
    return base::Vector3d(distanceError(_position, param), headingError(_heading, param), param);
}

void LocationWidget::setDirection(const Base::Vector3d& dir)
{
    if (dir.Length() < Base::Vector3d::epsilon()) {
        return;
    }

    // check if the user-defined direction is already there
    for (int i=0; i<dValue->count()-1; i++) {
        QVariant data = dValue->itemData (i);
        if (data.canConvert<Base::Vector3d>()) {
            const Base::Vector3d val = data.value<Base::Vector3d>();
            if (val == dir) {
                dValue->setCurrentIndex(i);
                return;
            }
        }
    }

    // add a new item before the very last item
    QString display = QString::fromLatin1("(%1,%2,%3)")
        .arg(dir.x)
        .arg(dir.y)
        .arg(dir.z);
    dValue->insertItem(dValue->count()-1, display,
        QVariant::fromValue<Base::Vector3d>(dir));
    dValue->setCurrentIndex(dValue->count()-2);
}

Base::Matrix4D MeshObject::getEigenSystem(Base::Vector3d& v) const
{
    MeshCore::MeshEigensystem cMeshEval(_kernel);
    cMeshEval.Evaluate();
    Base::Vector3f uvw = cMeshEval.GetBoundings();
    v.Set(uvw.x, uvw.y, uvw.z);
    return cMeshEval.Transform();
}

void LocationWidget::on_direction_activated(int index)
{
    // last item is selected to define direction by user
    if (index+1 == dValue->count()) {
        bool ok;
        Base::Vector3d dir = this->getUserDirection(&ok);
        if (ok) {
            if (dir.Length() < Base::Vector3d::epsilon()) {
                QMessageBox::critical(this, LocationDialog::tr("Wrong direction"),
                    LocationDialog::tr("Direction must not be the null vector"));
                return;
            }

            setDirection(dir);
        }
    }
}

//! calculate the section Normal/Projection Direction given baseView projection direction and section name
Base::Vector3d DrawViewSection::getSectionVector (const std::string sectionName)
{
    Base::Vector3d result;
    Base::Vector3d stdX(1.0,0.0,0.0);
    Base::Vector3d stdY(0.0,1.0,0.0);
    Base::Vector3d stdZ(0.0,0.0,1.0);

    double adjustAngle = 0.0;
    if (getBaseDPGI() != nullptr) {
        adjustAngle = getBaseDPGI()->getRotateAngle();
    }

    Base::Vector3d view = getBaseDVP()->Direction.getValue();
    view.Normalize();
    Base::Vector3d left = view.Cross(stdZ);
    left.Normalize();
    Base::Vector3d up = view.Cross(left);
    up.Normalize();
    double dot = view.Dot(stdZ);

    if (sectionName == "Up") {
        result = up;
        if (DrawUtil::fpCompare(dot,1.0)) {            //view = stdZ
            result = (-1.0 * stdY);
        } else if (DrawUtil::fpCompare(dot,-1.0)) {    //view = -stdZ
            result = stdY;
        }
    } else if (sectionName == "Down") {
        result = up * -1.0;
        if (DrawUtil::fpCompare(dot,1.0)) {            //view = stdZ
            result = stdY;
        } else if (DrawUtil::fpCompare(dot, -1.0)) {   //view = -stdZ
            result = (-1.0 * stdY);
        }
    } else if (sectionName == "Left") {
        result = left * -1.0;
        if (DrawUtil::fpCompare(fabs(dot),1.0)) {      //view = +/- stdZ
            result = stdX;
        }
    } else if (sectionName == "Right") {
        result = left;
        if (DrawUtil::fpCompare(fabs(dot),1.0)) {
            result = -1.0 * stdX;
        }
    } else {
        Base::Console().Log("Error - DVS::getSectionVector - bad sectionName: %s\n",sectionName.c_str());
        result = stdZ;
    }
    Base::Vector3d adjResult = DrawUtil::vecRotate(result,adjustAngle,view);
    return adjResult;
}

void ConstraintForce::onChanged(const App::Property* prop)
{
    // Note: If we call this at the end, then the arrows are not oriented correctly initially
    // because the NormalDirection has not been calculated yet
    Constraint::onChanged(prop);

    if (prop == &References) {
        std::vector<Base::Vector3d> points;
        std::vector<Base::Vector3d> normals;
        if (getPoints(points, normals)) {
            Points.setValues(points); // We don't use the normals because all arrows should have the same direction
        }
    } else if (prop == &Direction) {
        Base::Vector3d direction = getDirection(Direction);
        if (direction.Length() < Precision::Confusion())
            return;
        naturalDirectionVector = direction;
        if (Reversed.getValue())
            direction = -direction;
        DirectionVector.setValue(direction);
    } else if (prop == &Reversed) {
        // if the direction is invalid try to compute it again
        if (naturalDirectionVector.Length() < Precision::Confusion()) {
            naturalDirectionVector = getDirection(Direction);
        }
        if (naturalDirectionVector.Length() >= Precision::Confusion()) {
            if (Reversed.getValue() && (DirectionVector.getValue() == naturalDirectionVector)) {
                DirectionVector.setValue(-naturalDirectionVector);
            } else if (!Reversed.getValue() && (DirectionVector.getValue() != naturalDirectionVector)) {
                DirectionVector.setValue(naturalDirectionVector);
            }
        }
    } else if (prop == &NormalDirection) {
        // Set a default direction if no direction reference has been given
        if (Direction.getValue() == NULL) {
            Base::Vector3d direction = NormalDirection.getValue();
            if (Reversed.getValue())
                direction = -direction;
            DirectionVector.setValue(direction);
            naturalDirectionVector = direction;
        }
    }
}

bool Extrusion::fetchAxisLink(const App::PropertyLinkSub& axisLink, Base::Vector3d& basepoint, Base::Vector3d& dir)
{
    if (!axisLink.getValue())
        return false;

    if (!axisLink.getValue()->isDerivedFrom(Part::Feature::getClassTypeId()))
        throw Base::TypeError("AxisLink has no OCC shape");

    Part::Feature* linked = static_cast<Part::Feature*>(axisLink.getValue());

    TopoDS_Shape axEdge;
    if (axisLink.getSubValues().size() > 0  &&  axisLink.getSubValues()[0].length() > 0){
        axEdge = linked->Shape.getShape().getSubShape(axisLink.getSubValues()[0].c_str());
    } else {
        axEdge = linked->Shape.getValue();
    }

    if (axEdge.IsNull())
        throw Base::ValueError("DirLink shape is null");
    if (axEdge.ShapeType() != TopAbs_EDGE)
        throw Base::TypeError("DirLink shape is not an edge");

    BRepAdaptor_Curve crv(TopoDS::Edge(axEdge));
    gp_Pnt startpoint;
    gp_Pnt endpoint;
    if (crv.GetType() == GeomAbs_Line){
        startpoint = crv.Value(crv.FirstParameter());
        endpoint = crv.Value(crv.LastParameter());
        if (axEdge.Orientation() == TopAbs_REVERSED)
            std::swap(startpoint, endpoint);
    } else {
        throw Base::TypeError("DirLink edge is not a line.");
    }
    basepoint.Set(startpoint.X(), startpoint.Y(), startpoint.Z());
    gp_Vec vec = gp_Vec(startpoint, endpoint);
    dir.Set(vec.X(), vec.Y(), vec.Z());
    return true;
}

PyObject*  MeshPointPy::move(PyObject *args)
{
    if (!getMeshPointPtr()->isBound())
        PyErr_SetString(Base::BaseExceptionFreeCADError, "This object is not bounded to a mesh, so no topological operation is possible!");

    double  x=0.0,y=0.0,z=0.0;
    PyObject *object;
    Base::Vector3d vec;
    if (PyArg_ParseTuple(args, "ddd", &x,&y,&z)) {
        vec.Set(x,y,z);
    } 
    else if (PyArg_ParseTuple(args,"O!",&(Base::VectorPy::Type), &object)) {
        PyErr_Clear(); // set by PyArg_ParseTuple()
        // Note: must be static_cast, not reinterpret_cast
        vec = *(static_cast<Base::VectorPy*>(object)->getVectorPtr());
    }
    else {
        return 0;
    }

    getMeshPointPtr()->Mesh->movePoint(getMeshPointPtr()->Index,vec);
    Py_Return;
}

void ConstraintGear::onChanged(const App::Property* prop)
{
    ConstraintBearing::onChanged(prop);

    if (prop == &Direction) {
        Base::Vector3d direction = getDirection(Direction);
        if (direction.Length() < Precision::Confusion())
            return;
        naturalDirectionVector = direction;
        if (Reversed.getValue())
            direction = -direction;
        DirectionVector.setValue(direction);
        DirectionVector.touch();
    } else if (prop == &Reversed) {
        if (Reversed.getValue() && (DirectionVector.getValue() == naturalDirectionVector)) {
            DirectionVector.setValue(-naturalDirectionVector);
            DirectionVector.touch();
        } else if (!Reversed.getValue() && (DirectionVector.getValue() != naturalDirectionVector)) {
            DirectionVector.setValue(naturalDirectionVector);
            DirectionVector.touch();
        }
    }
    // The computation for the force angle is simpler in the ViewProvider directly
}

bool ViewProviderMirror::setEdit(int ModNum)
{
    if (ModNum == ViewProvider::Default) {
        // get the properties from the mirror feature
        Part::Mirroring* mf = static_cast<Part::Mirroring*>(getObject());
        Base::BoundBox3d bbox = mf->Shape.getBoundingBox();
        float len = (float)bbox.CalcDiagonalLength();
        Base::Vector3d base = mf->Base.getValue();
        Base::Vector3d norm = mf->Normal.getValue();
        Base::Vector3d cent = bbox.GetCenter();
        base = cent.ProjToPlane(base, norm);

        // setup the graph for editing the mirror plane
        SoTransform* trans = new SoTransform;
        SbRotation rot(SbVec3f(0,0,1), SbVec3f(norm.x,norm.y,norm.z));
        trans->rotation.setValue(rot);
        trans->translation.setValue(base.x,base.y,base.z);
        trans->center.setValue(0.0f,0.0f,0.0f);

        SoMaterial* color = new SoMaterial();
        color->diffuseColor.setValue(0,0,1);
        color->transparency.setValue(0.5);
        SoCoordinate3* points = new SoCoordinate3();
        points->point.setNum(4);
        points->point.set1Value(0, -len/2,-len/2,0);
        points->point.set1Value(1,  len/2,-len/2,0);
        points->point.set1Value(2,  len/2, len/2,0);
        points->point.set1Value(3, -len/2, len/2,0);
        SoFaceSet* face = new SoFaceSet();
        pcEditNode->addChild(trans);
        pcEditNode->addChild(color);
        pcEditNode->addChild(points);
        pcEditNode->addChild(face);

        // Now we replace the SoTransform node by a manipulator
        // Note: Even SoCenterballManip inherits from SoTransform
        // we cannot use it directly (in above code) because the
        // translation and center fields are overridden.
        SoSearchAction sa;
        sa.setInterest(SoSearchAction::FIRST);
        sa.setSearchingAll(FALSE);
        sa.setNode(trans);
        sa.apply(pcEditNode);
        SoPath * path = sa.getPath();
        if (path) {
            SoCenterballManip * manip = new SoCenterballManip;
            manip->replaceNode(path);

            SoDragger* dragger = manip->getDragger();
            dragger->addStartCallback(dragStartCallback, this);
            dragger->addFinishCallback(dragFinishCallback, this);
            dragger->addMotionCallback(dragMotionCallback, this);
        }
        pcRoot->addChild(pcEditNode);
    }
    else {
        ViewProviderPart::setEdit(ModNum);
    }

    return true;
}

int DrawSketchHandler::seekAutoConstraint(std::vector<AutoConstraint> &suggestedConstraints,
                                          const Base::Vector2D& Pos, const Base::Vector2D& Dir,
                                          AutoConstraint::TargetType type)
{
    suggestedConstraints.clear();

    if (!sketchgui->Autoconstraints.getValue())
        return 0; // If Autoconstraints property is not set quit

    Base::Vector3d hitShapeDir = Base::Vector3d(0,0,0); // direction of hit shape (if it is a line, the direction of the line)
        
    // Get Preselection
    int preSelPnt = sketchgui->getPreselectPoint();
    int preSelCrv = sketchgui->getPreselectCurve();
    int preSelCrs = sketchgui->getPreselectCross();
    int GeoId = Constraint::GeoUndef;
    Sketcher::PointPos PosId = Sketcher::none;
    if (preSelPnt != -1)
        sketchgui->getSketchObject()->getGeoVertexIndex(preSelPnt, GeoId, PosId);
    else if (preSelCrv != -1){
        GeoId = preSelCrv;
        const Part::Geometry *geom = sketchgui->getSketchObject()->getGeometry(GeoId);
        
        if(geom->getTypeId() == Part::GeomLineSegment::getClassTypeId()){
            const Part::GeomLineSegment *line = static_cast<const Part::GeomLineSegment *>(geom);
            hitShapeDir= line->getEndPoint()-line->getStartPoint();     
        }
            
    }
    else if (preSelCrs == 0) { // root point
        GeoId = -1;
        PosId = Sketcher::start;
    }
    else if (preSelCrs == 1){ // x axis
        GeoId = -1;
        hitShapeDir = Base::Vector3d(1,0,0);
        
    }
    else if (preSelCrs == 2){ // y axis
        GeoId = -2;
        hitShapeDir = Base::Vector3d(0,1,0);
    }

    if (GeoId != Constraint::GeoUndef) {
        // Currently only considers objects in current Sketcher
        AutoConstraint constr;
        constr.Type = Sketcher::None;
        constr.GeoId = GeoId;
        constr.PosId = PosId;
        if (type == AutoConstraint::VERTEX && PosId != Sketcher::none)
            constr.Type = Sketcher::Coincident;
        else if (type == AutoConstraint::CURVE && PosId != Sketcher::none)
            constr.Type = Sketcher::PointOnObject;
        else if (type == AutoConstraint::VERTEX && PosId == Sketcher::none)
            constr.Type = Sketcher::PointOnObject;
        else if (type == AutoConstraint::CURVE && PosId == Sketcher::none)
            constr.Type = Sketcher::Tangent;
        
        if(constr.Type == Sketcher::Tangent && Dir.Length() > 1e-8 && hitShapeDir.Length() > 1e-8) { // We are hitting a line and have hitting vector information
            Base::Vector3d dir3d = Base::Vector3d(Dir.fX,Dir.fY,0);
            double cosangle=dir3d.Normalize()*hitShapeDir.Normalize();
            
            // the angle between the line and the hitting direction are over around 6 degrees (it is substantially parallel)
            // or if it is an sketch axis (that can not move to accomodate to the shape), then only if it is around 6 degrees with the normal (around 84 degrees)
            if (fabs(cosangle) < 0.995f || ((GeoId==-1 || GeoId==-2) && fabs(cosangle) < 0.1))
                suggestedConstraints.push_back(constr);
            
            
            return suggestedConstraints.size();
        }

        if (constr.Type != Sketcher::None)
            suggestedConstraints.push_back(constr);
    }
        
    if (Dir.Length() < 1e-8 || type == AutoConstraint::CURVE)
        // Direction not set so return;
        return suggestedConstraints.size();

    // Suggest vertical and horizontal constraints

    // Number of Degree of deviation from horizontal or vertical lines
    const double angleDev = 2;
    const double angleDevRad = angleDev *  M_PI / 180.;

    AutoConstraint constr;
    constr.Type = Sketcher::None;
    constr.GeoId = Constraint::GeoUndef;
    constr.PosId = Sketcher::none;
    double angle = std::abs(atan2(Dir.fY, Dir.fX));
    if (angle < angleDevRad || (M_PI - angle) < angleDevRad )
        // Suggest horizontal constraint
        constr.Type = Sketcher::Horizontal;
    else if (std::abs(angle - M_PI_2) < angleDevRad)
        // Suggest vertical constraint
        constr.Type = Sketcher::Vertical;

    if (constr.Type != Sketcher::None)
        suggestedConstraints.push_back(constr);

//.........这里部分代码省略.........

// Methods for distances (edge length, two points, edge and a point
double Measurement::length() const
{
  int numRefs =  References3D.getSize();
  if(!numRefs || measureType == Invalid) {
      throw Base::Exception("Measurement - length - Invalid References3D Provided");
  }

  double result = 0.0;
  const std::vector<App::DocumentObject*> &objects = References3D.getValues();
  const std::vector<std::string> &subElements = References3D.getSubValues();

  if(measureType == Points ||
     measureType == PointToEdge ||
     measureType == PointToSurface)  {

      Base::Vector3d diff = this->delta();
      //return diff.Length();
      result = diff.Length();
  } else if(measureType == Edges) {

      double length = 0.f;
      // Iterate through edges and calculate each length
      std::vector<App::DocumentObject*>::const_iterator obj = objects.begin();
      std::vector<std::string>::const_iterator subEl = subElements.begin();

      for (;obj != objects.end(); ++obj, ++subEl) {
          //const Part::Feature *refObj = static_cast<const Part::Feature*>((*obj));
          //const Part::TopoShape& refShape = refObj->Shape.getShape();
          // Get the length of one edge
          TopoDS_Shape shape = getShape(*obj, (*subEl).c_str());
          const TopoDS_Edge& edge = TopoDS::Edge(shape);
          BRepAdaptor_Curve curve(edge);

          switch(curve.GetType()) {
            case GeomAbs_Line : {
                gp_Pnt P1 = curve.Value(curve.FirstParameter());
                gp_Pnt P2 = curve.Value(curve.LastParameter());
                gp_XYZ diff = P2.XYZ() - P1.XYZ();
                length += diff.Modulus();
            } break;
            case GeomAbs_Circle : {
                double u = curve.FirstParameter();
                double v = curve.LastParameter();
                double radius = curve.Circle().Radius();
                if (u > v) // if arc is reversed
                    std::swap(u, v);

                double range = v-u;
                length += radius * range;
            } break;
            case GeomAbs_Ellipse:
            case GeomAbs_BSplineCurve:
            case GeomAbs_Hyperbola:
            case GeomAbs_BezierCurve: {
                length += GCPnts_AbscissaPoint::Length(curve);
            } break;
            default: {
                throw Base::Exception("Measurement - length - Curve type not currently handled");
            }
          }
      }
      result = length;
      //return length;
  }
  return result;
}

    Py::Object makeFilletArc(const Py::Tuple& args)
    {
        PyObject *pM1;
        PyObject *pP;
        PyObject *pQ;
        PyObject *pN;
        double r2;
        int ccw;
        if (!PyArg_ParseTuple(args.ptr(), "O!O!O!O!di",
                &(Base::VectorPy::Type), &pM1,
                &(Base::VectorPy::Type), &pP,
                &(Base::VectorPy::Type), &pQ,
                &(Base::VectorPy::Type), &pN,
                &r2, &ccw))
            throw Py::Exception();

        Base::Vector3d M1 = Py::Vector(pM1, false).toVector();
        Base::Vector3d P  = Py::Vector(pP,  false).toVector();
        Base::Vector3d Q  = Py::Vector(pQ,  false).toVector();
        Base::Vector3d N  = Py::Vector(pN,  false).toVector();

        Base::Vector3d u = Q - P;
        Base::Vector3d v = P - M1;
        Base::Vector3d b;
        if (ccw)
            b = u % N;
        else
            b = N % u;
        b.Normalize();

        double uu = u * u;
        double uv = u * v;
        double r1 = v.Length();

        // distinguish between internal and external fillets
        r2 *= Base::sgn(uv);

        double cc = 2.0 * r2 * (b * v - r1);
        double d = uv * uv - uu * cc;
        if (d < 0) {
            throw Py::RuntimeError("Unable to calculate intersection points");
        }

        double t;
        double t1 = (-uv + sqrt(d)) / uu;
        double t2 = (-uv - sqrt(d)) / uu;

        if (fabs(t1) < fabs(t2))
            t = t1;
        else
            t = t2;

        Base::Vector3d M2 = P + (u*t) + (b*r2);
        Base::Vector3d S1 = (r2 * M1 + r1 * M2)/(r1+r2);
        Base::Vector3d S2 = M2 - (b*r2);

        Py::Tuple tuple(3);
        tuple.setItem(0, Py::Vector(S1));
        tuple.setItem(1, Py::Vector(S2));
        tuple.setItem(2, Py::Vector(M2));

        return tuple;
    }