diff --git a/EGkDistPointArc.h b/EGkDistPointArc.h
new file mode 100644
index 0000000..88a52bb
--- /dev/null
+++ b/EGkDistPointArc.h
@@ -0,0 +1,51 @@
+//----------------------------------------------------------------------------
+//  EgalTech 2013-2013
+//----------------------------------------------------------------------------
+// File : EGkDistPointArc.h      Data : 28.12.13          Versione : 1.4l5
+// Contenuto : Dichiarazione della classe distanza punto da circonferenza/arco.
+//
+//
+//
+// Modifiche : 28.12.13 DS Creazione modulo.
+//
+//
+//----------------------------------------------------------------------------
+
+#pragma once
+
+#include "/EgtDev/Include/EGkPoint3d.h"
+#include "/EgtDev/Include/EGkCurveArc.h"
+
+//----------------------- Macro per import/export ----------------------------
+#undef EGK_EXPORT
+#if defined( I_AM_EGK)            // da definirsi solo nella DLL
+   #define EGK_EXPORT __declspec( dllexport)
+#else
+   #define EGK_EXPORT __declspec( dllimport)
+#endif
+
+
+//-----------------------------------------------------------------------------
+class DistPointArc
+{
+   public :
+      EGK_EXPORT DistPointArc( const Point3d& ptP, const ICurveArc& arArc) ;
+
+   public :
+      EGK_EXPORT bool GetSqDist( double& dSqDist) ;
+      EGK_EXPORT bool GetDist( double& dDist) ;
+      EGK_EXPORT bool GetPointMinDist( Point3d& ptMinDist, bool* pbDet = nullptr) ;
+      EGK_EXPORT bool GetParamAtPointMinDist( double& dParam, bool* pbDet = nullptr) ;
+
+   private :
+      DistPointArc( void) ;
+      void DistPointCircle( const Point3d& ptP, const ICurveArc& arArc) ;
+      void DistPointFlatArc( const Point3d& ptP, const ICurveArc& arArc) ;
+
+   private :
+      bool    m_bDet ;
+      double  m_dDist ;
+      double  m_dParam ;
+      Point3d m_ptMinDist ;
+} ;
+
diff --git a/EGkDistPointLine.h b/EGkDistPointLine.h
index 9ac84e6..c9ca5c7 100644
--- a/EGkDistPointLine.h
+++ b/EGkDistPointLine.h
@@ -14,6 +14,7 @@
 #pragma once
 
 #include "/EgtDev/Include/EGkPoint3d.h"
+#include "/EgtDev/Include/EGkCurveLine.h"
 
 //----------------------- Macro per import/export ----------------------------
 #undef EGK_EXPORT
@@ -28,27 +29,29 @@
 class DistPointLine
 {
    public :
-      EGK_EXPORT DistPointLine( void) ;
+      EGK_EXPORT DistPointLine( const Point3d& ptP,
+                                const ICurveLine& crvLine, bool bIsSegment = true) ;
+      EGK_EXPORT DistPointLine( const Point3d& ptP,
+                                const Point3d& ptIni, const Point3d& ptFin, bool bIsSegment = true) ;
+      EGK_EXPORT DistPointLine( const Point3d& ptP,
+                                const Point3d& ptIni, const Vector3d& vtDir, double dLen, bool bIsSegment = true)
+                    { Calculate( ptP, ptIni, vtDir, dLen, bIsSegment) ; }
 
    public :
-      EGK_EXPORT bool Set( const Point3d& ptP, const Point3d& ptIni, const Point3d& ptFin, bool bIsSegment) ;
-      EGK_EXPORT bool SetPoint( const Point3d& ptP) ;
-      EGK_EXPORT bool SetLine( const Point3d& ptIni, const Point3d& ptFin, bool bIsSegment) ;
-      EGK_EXPORT double GetSqDist( void) ;
-      EGK_EXPORT double GetDist( void) ;
-      EGK_EXPORT const Point3d& GetPointMinDist( void) ;
+      EGK_EXPORT bool GetSqDist( double& dSqDist) ;
+      EGK_EXPORT bool GetDist( double& dDist) ;
+      EGK_EXPORT bool GetPointMinDist( Point3d& ptMinDist) ;
+      EGK_EXPORT bool GetParamAtPointMinDist( double& dParam) ;
 
    private :
-      bool Calculate( void) ;
+      DistPointLine( void) ;
+      void Calculate( const Point3d& ptP,
+                      const Point3d& ptIni, const Vector3d& vtDir, double dLen, bool bIsSegment) ;
 
    private :
-      Point3d  m_ptP ;
-      Point3d  m_ptIni ;
-      Vector3d m_vtDir ;
-      double   m_dLen ;
-      bool     m_bIsSegment ;
-      double   m_dSqDist ;
-      double   m_dDist ;
-      Point3d  m_ptMinDist ;
+      double  m_dSqDist ;
+      double  m_dDist ;
+      double  m_dParam ;
+      Point3d m_ptMinDist ;
 } ;
 
diff --git a/EGkFrame3d.h b/EGkFrame3d.h
index bf6fdcb..1490658 100644
--- a/EGkFrame3d.h
+++ b/EGkFrame3d.h
@@ -43,8 +43,8 @@ class EGK_EXPORT Frame3d
       // Mirror non possibile (cambia il senso destrorso in sinistrorso)
       bool ToGlob( const Frame3d& frRef) ;
       bool ToLoc( const Frame3d& frRef) ;
-      const Frame3d operator*=( const Frame3d& frRef) { this->ToGlob( frRef) ; return *this ;}
-      const Frame3d operator/=( const Frame3d& frRef) { this->ToLoc( frRef) ; return *this ;}
+      const Frame3d& operator*=( const Frame3d& frRef) { this->ToGlob( frRef) ; return *this ;}
+      const Frame3d& operator/=( const Frame3d& frRef) { this->ToLoc( frRef) ; return *this ;}
       int GetType( void) const { return m_nType ;}
       int GetZType( void) const { return m_nZType ;}
       const Point3d& Orig( void) const { return m_ptOrig ;}
diff --git a/EGkGdbIterator.h b/EGkGdbIterator.h
index 03db02a..37d5749 100644
--- a/EGkGdbIterator.h
+++ b/EGkGdbIterator.h
@@ -41,6 +41,7 @@ class __declspec( novtable) IGdbIterator
       virtual bool GetGroupGlobFrame( Frame3d& frGlob) = 0 ;
       virtual int  GetId( void) = 0 ;
       virtual int  GetParentId( void) = 0 ;
+      virtual bool GetGlobFrame( Frame3d& frGlob) = 0 ;
 } ;
 
 //-----------------------------------------------------------------------------
diff --git a/EGkGeomDB.h b/EGkGeomDB.h
index 4db9ff1..f1fc9cf 100644
--- a/EGkGeomDB.h
+++ b/EGkGeomDB.h
@@ -43,6 +43,7 @@ class __declspec( novtable) IGeomDB
       virtual Frame3d* GetGroupFrame( int nId) = 0 ;
       virtual bool GetGroupGlobFrame( int nId, Frame3d& frGlob) = 0 ;
       virtual int  GetParentId( int nId) = 0 ;
+      virtual bool GetGlobFrame( int nId, Frame3d& frGlob) = 0 ;
       virtual int  Copy( int nIdSou, int nIdDest, int nParentIdDest) = 0 ;
       virtual bool Erase( int nId) = 0 ;
       virtual bool Translate( int nId, const Vector3d& vtMove) = 0 ;
diff --git a/EGkPoint3d.h b/EGkPoint3d.h
index 3650743..2696d90 100644
--- a/EGkPoint3d.h
+++ b/EGkPoint3d.h
@@ -30,9 +30,9 @@ class Frame3d ;
 class EGK_EXPORT Point3d
 {
    public :
-      Point3d( double dX, double dY, double dZ) { x = dX ; y = dY ; z = dZ ;}
-      Point3d( double dX, double dY) { x = dX ; y = dY ; z = 0 ;}
-      Point3d( void) { x = 0 ; y = 0 ; z = 0 ;}
+      Point3d( double dX, double dY, double dZ) : x( dX), y( dY), z( dZ) {}
+      Point3d( double dX, double dY) : x( dX), y( dY), z( 0) {}
+      Point3d( void) : x( 0), y( 0), z( 0) {}
       void Set( double dX, double dY, double dZ) { x = dX ; y = dY ; z = dZ ;}
       const Point3d& operator =( const Point3d& ptSrc)
                      { if ( &ptSrc != this) {
@@ -40,6 +40,15 @@ class EGK_EXPORT Point3d
                        return *this ; }
 
    public :
+      const Point3d& operator +=( const Vector3d& vtV)
+             { this->x += vtV.x ; this->y += vtV.y ; this->z += vtV.z ; return *this ; }
+      // questa somma è valida solo se equivalente ad una combinazione baricentrica
+      const Point3d& operator +=( const Point3d& ptP)
+             { this->x += ptP.x ; this->y += ptP.y ; this->z += ptP.z ; return *this ; }
+      const Point3d& operator *=( double dMul)
+             { this->x *= dMul ; this->y *= dMul ; this->z *= dMul ; return *this ; }
+      const Point3d& operator /=( double dDiv)
+             { double dMul = 1 / dDiv ; this->x *= dMul ; this->y *= dMul ; this->z *= dMul ; return *this ; }
       void Translate( const Vector3d& vtMove) ;
       bool Rotate( const Point3d& ptAx, const Vector3d& vtAx, double dAngRad) ;
       bool Rotate( const Point3d& ptAx, const Vector3d& vtAx, double dCosAng, double dSinAng) ;
@@ -47,6 +56,8 @@ class EGK_EXPORT Point3d
       bool Mirror( const Point3d& ptOn, const Vector3d& vtNorm) ;
       bool ToGlob( const Frame3d& frRef) ;
       bool ToLoc( const Frame3d& frRef) ;
+      bool LocToLoc( const Frame3d& frOri, const Frame3d& frDest)
+             { return ( ToGlob( frOri)  &&  ToLoc( frDest)) ; }
 
    public :
       double x ;
@@ -165,6 +176,25 @@ Dist( const Point3d& ptP1, const Point3d& ptP2)
    return sqrt( dX * dX + dY * dY + dZ * dZ) ; 
 }
 
+//----------------------------------------------------------------------------
+// Direzione e distanza tra due punti
+//----------------------------------------------------------------------------
+inline bool
+DirDist( const Point3d& ptP1, const Point3d& ptP2, Vector3d& vtDir, double& dDist)
+{
+   dDist = Dist( ptP1, ptP2) ;
+
+  // se distanza significativa
+   if ( dDist > EPS_SMALL) {
+      vtDir = ( ptP2 - ptP1) / dDist ;
+      return true ;
+   }
+
+  // punti praticamente coincidenti
+   vtDir.Set( 0, 0, 0) ;
+   return false ;
+}
+
 //----------------------------------------------------------------------------
 // Verifica che due punti sono quasi coincidenti (Small error -> Near)
 //----------------------------------------------------------------------------
diff --git a/EGkPolyLine.h b/EGkPolyLine.h
index 1978ac9..74b601e 100644
--- a/EGkPolyLine.h
+++ b/EGkPolyLine.h
@@ -1,7 +1,7 @@
 //----------------------------------------------------------------------------
 //  EgalTech 2013-2013
 //----------------------------------------------------------------------------
-// File : DistPointLine.cpp       Data : 22.12.13          Versione : 1.4l3
+// File : EGkPolyLine.cpp       Data : 22.12.13          Versione : 1.4l3
 // Contenuto : Dichiarazione della classe PolyLine.
 //
 //
diff --git a/EGkVector3d.h b/EGkVector3d.h
index b226150..1bafa2f 100644
--- a/EGkVector3d.h
+++ b/EGkVector3d.h
@@ -30,9 +30,9 @@ class Frame3d ;
 class EGK_EXPORT Vector3d
 {
    public :
-      Vector3d( double dX, double dY, double dZ) { x = dX ; y = dY ; z = dZ ;}
-      Vector3d( double dX, double dY) { x = dX ; y = dY ; z = 0 ;}
-      Vector3d( void) { x = 0 ; y = 0 ; z = 0 ;}
+      Vector3d( double dX, double dY, double dZ) : x( dX), y( dY), z( dZ) {}
+      Vector3d( double dX, double dY) : x( dX), y( dY), z( 0) {}
+      Vector3d( void) : x( 0), y( 0), z( 0) {}
       void Set( double dX, double dY, double dZ) { x = dX ; y = dY ; z = dZ ;}
       const Vector3d& operator =( const Vector3d& vtSrc)
                          { if ( &vtSrc != this) {
@@ -54,16 +54,26 @@ class EGK_EXPORT Vector3d
              { return ( fabs( x) < EPS_ZERO  &&  fabs( y) < EPS_ZERO  &&  z > EPS_ZERO) ; }
       bool IsZminus( void) const
              { return ( fabs( x) < EPS_ZERO  &&  fabs( y) < EPS_ZERO  &&  z < - EPS_ZERO) ; }
+      const Vector3d& operator +=( const Vector3d& vtV)
+             { this->x += vtV.x ; this->y += vtV.y ; this->z += vtV.z ; return *this ; }
+      const Vector3d& operator -=( const Vector3d& vtV)
+             { this->x -= vtV.x ; this->y -= vtV.y ; this->z -= vtV.z ; return *this ; }
+      const Vector3d& operator *=( double dMul)
+             { this->x *= dMul ; this->y *= dMul ; this->z *= dMul ; return *this ; }
+      const Vector3d& operator /=( double dDiv)
+             { double dMul = 1 / dDiv ; this->x *= dMul ; this->y *= dMul ; this->z *= dMul ; return *this ; }
       void ToSpherical( double* pdLen, double* pdAngVertDeg, double* pdAngOrizzDeg) const ;
-      bool   Normalize( void) ;
-      bool   Rotate( const Vector3d& vtAx, double dAngRad) ;
-      bool   Rotate( const Vector3d& vtAx, double dCosAng, double dSinAng) ;
-      bool   Scale( double dCoeffX, double dCoeffY, double dCoeffZ) ;
-      bool   Mirror( const Vector3d& vtNorm) ;
-      bool   ToGlob( const Frame3d& frRef) ;
-      bool   ToLoc( const Frame3d& frRef) ;
-      bool   GetAngle( const Vector3d& vtEnd, double& dAngDeg) ;
-      bool   GetRotation( const Vector3d& vtEnd, const Vector3d& vtAx, double& dAngDeg, bool& bDet) ;
+      bool Normalize( void) ;
+      bool Rotate( const Vector3d& vtAx, double dAngRad) ;
+      bool Rotate( const Vector3d& vtAx, double dCosAng, double dSinAng) ;
+      bool Scale( double dCoeffX, double dCoeffY, double dCoeffZ) ;
+      bool Mirror( const Vector3d& vtNorm) ;
+      bool ToGlob( const Frame3d& frRef) ;
+      bool ToLoc( const Frame3d& frRef) ;
+      bool LocToLoc( const Frame3d& frOri, const Frame3d& frDest)
+             { return ( ToGlob( frOri)  &&  ToLoc( frDest)) ; }
+      bool GetAngle( const Vector3d& vtEnd, double& dAngDeg) const ;
+      bool GetRotation( const Vector3d& vtEnd, const Vector3d& vtAx, double& dAngDeg, bool& bDet) const ;
 
    public :
       double x ;
@@ -170,9 +180,7 @@ Media( const Vector3d& vtV1, const Vector3d& vtV2, double dCoeff)
 inline bool
 AreSameVectorNear( const Vector3d& vtV1, const Vector3d& vtV2)
 {
-   return ( fabs( vtV1.x - vtV2.x) < EPS_SMALL  &&
-            fabs( vtV1.y - vtV2.y) < EPS_SMALL  &&
-            fabs( vtV1.z - vtV2.z) < EPS_SMALL) ;
+   return ( ( vtV1 - vtV2).IsSmall()) ;
 }
 
 //----------------------------------------------------------------------------
@@ -181,9 +189,7 @@ AreSameVectorNear( const Vector3d& vtV1, const Vector3d& vtV2)
 inline bool
 AreSameVectorExact( const Vector3d& vtV1, const Vector3d& vtV2)
 {
-   return ( fabs( vtV1.x - vtV2.x) < EPS_ZERO  &&
-            fabs( vtV1.y - vtV2.y) < EPS_ZERO  &&
-            fabs( vtV1.z - vtV2.z) < EPS_ZERO) ;
+   return ( ( vtV1 - vtV2).IsZero()) ;
 }
 
 //----------------------------------------------------------------------------
diff --git a/EgkCurve.h b/EgkCurve.h
index bc9d010..d481675 100644
--- a/EgkCurve.h
+++ b/EgkCurve.h
@@ -30,11 +30,11 @@ class __declspec( novtable) ICurve : public IGeoObj
       virtual bool GetEndPoint( Point3d& ptEnd) const = 0 ;
       virtual bool GetDomain( double& dStart, double& dEnd) const = 0 ;
       virtual bool GetLength( double& dLen) const = 0 ;
-      virtual bool GetPointD1D2( double dU, Side nS, Point3d& ptPos, Vector3d& vtDer1, Vector3d& vtDer2) const = 0 ;
-      virtual bool GetPoint( double dU, Side nS, Point3d& ptPos) const = 0 ;
+      virtual bool GetPointD1D2( double dU, Side nS, Point3d& ptPos,
+                                 Vector3d* pvtDer1 = nullptr, Vector3d* pvtDer2 = nullptr) const = 0 ;
       virtual bool GetPointTang( double dU, Side nS, Point3d& ptPos, Vector3d& vtTang) const = 0 ;
       virtual bool GetPointDiffGeom( double dU, Side nS, CrvPointDiffGeom& oDiffG) const = 0 ;
-      virtual bool Reverse( void) = 0 ;
+      virtual bool Invert( void) = 0 ;
       virtual bool ApproxWithLines( double dLinTol, double dAngTolDeg, PolyLine& PL) const = 0 ;
       virtual bool TrimStartAtParam( double dUTrim) = 0 ;
       virtual bool TrimEndAtParam( double dUTrim) = 0 ;
diff --git a/EgkCurveArc.h b/EgkCurveArc.h
index 2a39279..b4eac50 100644
--- a/EgkCurveArc.h
+++ b/EgkCurveArc.h
@@ -23,6 +23,8 @@ class __declspec( novtable) ICurveArc : public ICurve
                         const Vector3d& vtS, double dAngCenDeg, double dDeltaN) = 0 ;
       virtual bool Set( const Point3d& ptCen, double dRad, double dAngIniDeg, double dAngCenDeg, double dDeltaZ) = 0 ;
       virtual bool Set( const Point3d& ptCen, double dRad) = 0 ;
+      virtual bool IsFlat( void) const = 0 ;
+      virtual bool IsACircle( void) const = 0 ;
       virtual bool IsInPlaneXY( void) const = 0 ;
       virtual const Point3d& GetCenter( void) const = 0 ;
       virtual const Vector3d& GetNormVersor( void) const = 0 ;