diff --git a/EGkPolyLine.h b/EGkPolyLine.h
index ce31ebd..1718015 100644
--- a/EGkPolyLine.h
+++ b/EGkPolyLine.h
@@ -56,26 +56,31 @@ class PolyLine
                         { return m_nRejected ; }
       EGK_EXPORT int  GetPointNbr( void) const
                         { return m_nCount ; }
-      EGK_EXPORT bool GetFirstUPoint( double* pdPar, Point3d* pptP) const ;
+      EGK_EXPORT bool GetFirstUPoint( double* pdPar, Point3d* pptP, bool bNotLast = false) const ;
       EGK_EXPORT bool GetNextUPoint( double* pdPar, Point3d* pptP, bool bNotLast = false) const ;
-      EGK_EXPORT bool GetFirstU( double& dPar) const
-                        { return GetFirstUPoint( &dPar, nullptr) ; }
+      EGK_EXPORT bool GetFirstU( double& dPar, bool bNotLast = false) const
+                        { return GetFirstUPoint( &dPar, nullptr, bNotLast) ; }
       EGK_EXPORT bool GetNextU( double& dPar, bool bNotLast = false) const
                         { return GetNextUPoint( &dPar, nullptr, bNotLast) ; }
-      EGK_EXPORT bool GetFirstPoint( Point3d& ptP) const
-                        { return GetFirstUPoint( nullptr, &ptP) ; }
+      EGK_EXPORT bool GetFirstPoint( Point3d& ptP, bool bNotLast = false) const
+                        { return GetFirstUPoint( nullptr, &ptP, bNotLast) ; }
       EGK_EXPORT bool GetNextPoint( Point3d& ptP, bool bNotLast = false) const
                         { return GetNextUPoint( nullptr, &ptP, bNotLast) ; }
-      EGK_EXPORT bool GetLastUPoint( double* pdPar, Point3d* pptP) const ;
+      EGK_EXPORT bool GetLastUPoint( double* pdPar, Point3d* pptP, bool bNotFirst = false) const ;
       EGK_EXPORT bool GetPrevUPoint( double* pdPar, Point3d* pptP, bool bNotFirst = false) const ;
-      EGK_EXPORT bool GetLastU( double& dPar) const
-                        { return GetLastUPoint( &dPar, nullptr) ; }
+      EGK_EXPORT bool GetLastU( double& dPar, bool bNotFirst = false) const
+                        { return GetLastUPoint( &dPar, nullptr, bNotFirst) ; }
       EGK_EXPORT bool GetPrevU( double& dPar, bool bNotFirst = false) const
                         { return GetPrevUPoint( &dPar, nullptr, bNotFirst) ; }
-      EGK_EXPORT bool GetLastPoint( Point3d& ptP) const
-                        { return GetLastUPoint( nullptr, &ptP) ; }
+      EGK_EXPORT bool GetLastPoint( Point3d& ptP, bool bNotFirst = false) const
+                        { return GetLastUPoint( nullptr, &ptP, bNotFirst) ; }
       EGK_EXPORT bool GetPrevPoint( Point3d& ptP, bool bNotFirst = false) const
                         { return GetPrevUPoint( nullptr, &ptP, bNotFirst) ; }
+      EGK_EXPORT bool GetCurrUPoint( double* pdPar, Point3d* pptP) const ;
+      EGK_EXPORT bool GetCurrU( double& dPar) const
+                        { return GetCurrUPoint( &dPar, nullptr) ; }
+      EGK_EXPORT bool GetCurrPoint( Point3d& ptP) const
+                        { return GetCurrUPoint(  nullptr, &ptP) ; }
       EGK_EXPORT int  GetLineNbr( void) const
                         { return ( m_nCount > 1 ? ( m_nCount - 1) : 0) ; }
       EGK_EXPORT bool GetFirstULine( double* pdIni, Point3d* pptIni, double* pdFin, Point3d* pptFin) const ;
diff --git a/EGkVector3d.h b/EGkVector3d.h
index ae4f46f..8752c97 100644
--- a/EGkVector3d.h
+++ b/EGkVector3d.h
@@ -298,7 +298,7 @@ AreOppositeVectorApprox( const Vector3d& vtV1, const Vector3d& vtV2)
 }
 
 //----------------------------------------------------------------------------
-//! Verifica se due vettori sono esattamente coincidenti (Zero error -> Exact)
+//! Verifica se due vettori sono esattamente opposti (Zero error -> Exact)
 //----------------------------------------------------------------------------
 inline bool
 AreOppositeVectorExact( const Vector3d& vtV1, const Vector3d& vtV2)
@@ -306,6 +306,24 @@ AreOppositeVectorExact( const Vector3d& vtV1, const Vector3d& vtV2)
    return ( ( vtV1 + vtV2).IsZero()) ;
 }
 
+//----------------------------------------------------------------------------
+//! Verifica se due vettori sono quasi coincidenti o opposti (Zero error -> Exact)
+//----------------------------------------------------------------------------
+inline bool
+AreSameOrOppositeVectorApprox( const Vector3d& vtV1, const Vector3d& vtV2)
+{
+   return ( ( vtV1 - vtV2).IsSmall()  ||  ( vtV1 + vtV2).IsSmall()) ;
+}
+
+//----------------------------------------------------------------------------
+//! Verifica se due vettori sono esattamente coincidenti o opposti (Zero error -> Exact)
+//----------------------------------------------------------------------------
+inline bool
+AreSameOrOppositeVectorExact( const Vector3d& vtV1, const Vector3d& vtV2)
+{
+   return ( ( vtV1 - vtV2).IsZero()  ||  ( vtV1 + vtV2).IsZero()) ;
+}
+
 //----------------------------------------------------------------------------
 //! Verifica se due versori sono ortogonali (Small error -> Approx)
 //----------------------------------------------------------------------------
diff --git a/EgkCurve.h b/EgkCurve.h
index 2f64ca6..b9e8bbb 100644
--- a/EgkCurve.h
+++ b/EgkCurve.h
@@ -46,6 +46,8 @@ class __declspec( novtable) ICurve : public IGeoObj
       virtual bool GetStartDir( Vector3d& vtDir) const = 0 ;
       virtual bool GetEndDir( Vector3d& vtDir) const = 0 ;
       virtual bool GetMidDir( Vector3d& vtDir) const = 0 ;
+      virtual bool GetExtrusion( Vector3d& vtExtr) const = 0 ;
+      virtual bool GetThickness( double& dThick) const = 0 ;
       virtual bool GetDomain( double& dStart, double& dEnd) const = 0 ;
       virtual bool IsValidParam( double dPar, Side nSide) const = 0 ;
       virtual bool IsStartParam( double dPar) const = 0 ;
@@ -63,6 +65,8 @@ class __declspec( novtable) ICurve : public IGeoObj
       virtual ICurve* CopyParamRange( double dUStart, double dUEnd) const = 0 ;
       virtual bool Invert( void) = 0 ;
       virtual bool Offset( double dDist, int nSide, int nType = OFF_FILLET) = 0 ;
+      virtual bool SetExtrusion( const Vector3d& vtExtr) = 0 ;
+      virtual bool SetThickness( double dThick) = 0 ;
       virtual bool ModifyStart( const Point3d& ptNewStart) = 0 ;
       virtual bool ModifyEnd( const Point3d& ptNewEnd) = 0 ;
       virtual bool TrimStartAtParam( double dUTrim) = 0 ;