[Part] Add methods to create an arc of the curve

src/Mod/Part/App/Geometry.cpp

@@ -793,6 +793,11 @@ GeomBSplineCurve* GeomCurve::toNurbs(double first, double last) const
     return toBSpline(first, last);
 }
 
+GeomCurve* GeomCurve::createArc([[maybe_unused]] double first, [[maybe_unused]] double last) const
+{
+    return nullptr;
+}
+
 bool GeomCurve::tangent(double u, gp_Dir& dir) const
 {
     Handle(Geom_Curve) curve = Handle(Geom_Curve)::DownCast(handle());
@@ -1380,6 +1385,14 @@ Geometry *GeomBSplineCurve::copy() const
     }
 }
 
+GeomCurve* GeomBSplineCurve::createArc(double first, double last) const
+{
+   auto newBsp = static_cast<Part::GeomBSplineCurve*>(this->copy());
+   newBsp->Trim(first, last);
+
+   return newBsp;
+}
+
 int GeomBSplineCurve::countPoles() const
 {
     return myCurve->NbPoles();
@@ -2270,6 +2283,14 @@ Geometry *GeomTrimmedCurve::copy() const
     return newCurve;
 }
 
+GeomCurve* GeomTrimmedCurve::createArc(double first, double last) const
+{
+    auto newArc = static_cast<Part::GeomTrimmedCurve*>(this->copy());
+    newArc->setRange(first, last);
+
+    return newArc;
+}
+
 // Persistence implementer
 unsigned int GeomTrimmedCurve::getMemSize () const
 {
@@ -2592,6 +2613,14 @@ Geometry *GeomCircle::copy() const
     return newCirc;
 }
 
+GeomCurve* GeomCircle::createArc(double first, double last) const
+{
+    auto newArc = new GeomArcOfCircle(Handle(Geom_Circle)::DownCast(this->handle()->Copy()));
+    newArc->setRange(first, last, false);
+
+    return newArc;
+}
+
 GeomBSplineCurve* GeomCircle::toNurbs(double first, double last) const
 {
     // for an arc of circle use the generic method
@@ -3030,6 +3059,14 @@ Geometry *GeomEllipse::copy() const
     return newEllipse;
 }
 
+GeomCurve* GeomEllipse::createArc(double first, double last) const
+{
+    auto newArc = new GeomArcOfEllipse(Handle(Geom_Ellipse)::DownCast(this->handle()->Copy()));
+    newArc->setRange(first, last, false);
+
+    return newArc;
+}
+
 GeomBSplineCurve* GeomEllipse::toNurbs(double first, double last) const
 {
     // for an arc of ellipse use the generic method

src/Mod/Part/App/Geometry.h

@@ -209,8 +209,15 @@ public:
       The default implementation does the same as \ref toBSpline.
       In sub-classes this can be reimplemented to create a real
       NURBS curve and not just an approximation.
-     */
+    */
     virtual GeomBSplineCurve* toNurbs(double first, double last) const;
+    /*!
+     * \brief getArc Generates a curve that is an arc of this curve between given parameters
+     * \param first Parameter at start of arc
+     * \param last Parameter at end of arc. This may be < `first` for periodic curves.
+     * \return the new curve
+     */
+    virtual GeomCurve* createArc(double first, double last) const;
     bool tangent(double u, gp_Dir&) const;
     bool tangent(double u, Base::Vector3d& dir) const;
     Base::Vector3d pointAtParameter(double u) const;
@@ -294,6 +301,8 @@ public:
     ~GeomBSplineCurve() override;
     Geometry *copy() const override;
 
+    GeomCurve* createArc(double first, double last) const override;
+
    /*!
     * Interpolate a spline passing through the given points without tangency.
     */
@@ -430,6 +439,7 @@ public:
     ~GeomTrimmedCurve() override;
     Geometry *copy() const override;
 
+    GeomCurve* createArc(double first, double last) const override;
     // Persistence implementer ---------------------
     unsigned int getMemSize() const override;
     void Save(Base::Writer &/*writer*/) const override;
@@ -514,6 +524,7 @@ public:
     ~GeomCircle() override;
     Geometry *copy() const override;
 
+    GeomCurve* createArc(double first, double last) const override;
     double getRadius() const;
     void setRadius(double Radius);
 
@@ -575,6 +586,7 @@ public:
     ~GeomEllipse() override;
     Geometry *copy() const override;
 
+    GeomCurve* createArc(double first, double last) const override;
     double getMajorRadius() const;
     void setMajorRadius(double Radius);
     double getMinorRadius() const;