diff --git a/EGrScene.h b/EGrScene.h
index 37a7ebb..a05db50 100644
--- a/EGrScene.h
+++ b/EGrScene.h
@@ -16,6 +16,7 @@
 //----------------------------------------------------------------------------
 #include "/EgtDev/Include/EGkPoint3d.h"
 #include "/EgtDev/Include/EGkBBox3d.h"
+#include "/EgtDev/Include/EGkPlane3d.h"
 #include "/EgtDev/Include/EGkColor.h"
 #include "/EgtDev/Include/EgtNumCollection.h"
 #define NOMINMAX
@@ -41,26 +42,26 @@ class IEGrScene
       virtual ~IEGrScene( void) {}
       virtual bool Init( IGeomDB* pGeomDB) = 0 ;
       virtual bool CreateContext( HDC hDC, int nDriver, bool b2Buff, int nColorBits, int nDepthBits) = 0 ;
-      virtual bool IsValid( void) = 0 ;
-      virtual std::string GetOpenGLInfo( void) = 0 ;
-      virtual std::string GetGLSLInfo( void) = 0 ;
-      virtual std::string GetPixelFormatInfo( void) = 0 ;
-      virtual IGeomDB* GetGeomDB( void) = 0 ;
+      virtual bool IsValid( void) const = 0 ;
+      virtual std::string GetOpenGLInfo( void) const = 0 ;
+      virtual std::string GetGLSLInfo( void) const = 0 ;
+      virtual std::string GetPixelFormatInfo( void) const = 0 ;
+      virtual IGeomDB* GetGeomDB( void) const = 0 ;
       virtual bool RedrawWindow( void) = 0 ;
       virtual bool Resize( int nW, int nH) = 0 ;
       virtual bool SetBackground( Color colBackTop, Color colBackBottom) = 0 ;
       virtual bool Draw( void) = 0 ;
-      virtual bool Project( const Point3d& ptWorld, Point3d& ptView) = 0 ;
-      virtual bool UnProject( const Point3d& ptView, Point3d& ptWorld) = 0 ;
+      virtual bool Project( const Point3d& ptWorld, Point3d& ptView) const = 0 ;
+      virtual bool UnProject( const Point3d& ptView, Point3d& ptWorld) const = 0 ;
       virtual void Destroy( void) = 0 ;
      // Camera
       virtual bool SetCenter( const Point3d& ptCenter) = 0 ;
       virtual bool SetCamera( double dAngVertDeg, double dAngOrizzDeg, double dDist) = 0 ;
       virtual bool SetCamera( int nDir, double dDist = 0) = 0 ;
-      virtual const Point3d& GetCenter( void) = 0 ;
-      virtual Point3d GetProjectedCenter( void) = 0 ;
-      virtual void GetCamera( double* pdAngVertDeg, double* pdAngOrizzDeg, double* pdDist = nullptr) = 0 ;
-      virtual int  GetCameraDir( void) = 0 ;
+      virtual const Point3d& GetCenter( void) const = 0 ;
+      virtual Point3d GetProjectedCenter( void) const = 0 ;
+      virtual void GetCamera( double* pdAngVertDeg, double* pdAngOrizzDeg, double* pdDist = nullptr) const = 0 ;
+      virtual int  GetCameraDir( void) const = 0 ;
       virtual bool PanCamera( const Point3d& ptWinOld, const Point3d& ptWinNew) = 0 ;
       virtual bool RotateCamera( const Point3d& ptWinOld, const Point3d& ptWinNew) = 0 ;
       virtual bool ZoomAll( void) = 0 ;
@@ -70,13 +71,13 @@ class IEGrScene
       virtual bool ZoomWin( const Point3d& ptWin1, const Point3d& ptWin2) = 0 ;
      // ShowMode
       virtual bool SetShowMode( int nShowMode) = 0 ;
-      virtual int  GetShowMode( void) = 0 ;
+      virtual int  GetShowMode( void) const = 0 ;
       virtual void SetShowCurveDirection( bool bShow) = 0 ;
-      virtual bool GetShowCurveDirection( void) = 0 ;
+      virtual bool GetShowCurveDirection( void) const = 0 ;
       virtual void SetShowTriaAdvanced( bool bAdvanced)= 0 ;
-      virtual bool GetShowTriaAdvanced( void) = 0 ;
+      virtual bool GetShowTriaAdvanced( void) const = 0 ;
       virtual void SetShowZmap( int nMode) = 0 ;
-      virtual int  GetShowZmap( void) = 0 ;
+      virtual int  GetShowZmap( void) const = 0 ;
      // Geometry
       virtual bool SetExtension( const BBox3d& b3Ext) = 0 ;
       virtual bool UpdateExtension( void) = 0 ;
@@ -105,26 +106,27 @@ class IEGrScene
       virtual bool UnselectableRemove( int nId) = 0 ;
       virtual bool UnselectableClearAll( void) = 0 ;
       virtual bool UnselectableFind( int nId) = 0 ;
-      virtual bool GetSelectedObjs( INTVECTOR& nIds) = 0 ;
+      virtual bool GetSelectedObjs( INTVECTOR& nIds) const = 0 ;
       virtual int  GetFirstSelectedObj( void) = 0 ;
       virtual int  GetNextSelectedObj( void) = 0 ;
-      virtual double GetSelectedObjWinZ( int nSel = - 1) = 0 ;
-      virtual double GetSelectedObjMinWinZ( int nSel = - 1) = 0 ;
+      virtual double GetSelectedObjWinZ( int nSel = - 1) const = 0 ;
+      virtual double GetSelectedObjMinWinZ( int nSel = - 1) const = 0 ;
       virtual bool GetPointFromSelect( int nSelId, const Point3d& ptView, Point3d& ptSel, int& nAux) = 0 ;
      // Snap
       // anche per lo snap valgono SetObjFilterForSelect e Unselectable*
       virtual bool GetGraphicSnapPoint( int nSnap, const Point3d& ptWin, int nW, int nH, Point3d& ptSel) = 0 ;
-      virtual bool GetGridSnapPointZ( bool bSketch, const Point3d& ptWin, const Point3d& ptGrid, Point3d& ptSel) = 0 ;
-      virtual int  GetLastSnapId( void) = 0 ;
-      virtual bool GetLastSnapDir( Vector3d& vtDir) = 0 ;
+      virtual bool GetGridSnapPointZ( bool bSketch, const Point3d& ptWin, const Point3d& ptGrid, Point3d& ptSel) const = 0 ;
+      virtual int  GetLastSnapId( void) const = 0 ;
+      virtual bool GetLastSnapDir( Vector3d& vtDir) const = 0 ;
+      virtual bool GetPlaneSnapPoint( const Point3d& ptWin, const Plane3d& plPlane, Point3d& ptSel) const = 0 ;
      // Texture
       virtual bool LoadTexture( const std::string& sName, const std::string& sFile,
                                 double dMMxPix, double dDimX, double dDimY, int nRepeat) = 0 ;
       virtual bool UnloadTexture( const std::string& sName) = 0 ;
       virtual bool UnloadAllTextures( void) = 0 ;
-      virtual bool ExistsTexture( const std::string& sName) = 0 ;
-      virtual bool GetTexturePixels( const std::string& sName, int& nWidth, int& nHeight) = 0 ;
-      virtual bool GetTextureDimensions( const std::string& sName, double& dDimX, double& dDimY) = 0 ;
+      virtual bool ExistsTexture( const std::string& sName) const = 0 ;
+      virtual bool GetTexturePixels( const std::string& sName, int& nWidth, int& nHeight) const = 0 ;
+      virtual bool GetTextureDimensions( const std::string& sName, double& dDimX, double& dDimY) const = 0 ;
       virtual bool ChangeTextureDimensions( const std::string& sName, double dDimX, double dDimY) = 0 ;
 } ;
 
diff --git a/EInAPI.h b/EInAPI.h
index 2e14b89..c33e273 100644
--- a/EInAPI.h
+++ b/EInAPI.h
@@ -553,6 +553,7 @@ EIN_EXPORT BOOL __stdcall EgtModifyRawPartSize( int nRawId, double dLength, doub
 EIN_EXPORT BOOL __stdcall EgtModifyRawPartHeight( int nRawId, double dHeight) ;
 EIN_EXPORT BOOL __stdcall EgtKeepRawPart( int nRawId, int nSouPhase) ;
 EIN_EXPORT BOOL __stdcall EgtVerifyRawPartPhase( int nRawId, int nPhase) ;
+EIN_EXPORT BOOL __stdcall EgtVerifyRawPartCurrPhase( int nRawId) ;
 EIN_EXPORT BOOL __stdcall EgtRemoveRawPartFromCurrPhase( int nRawId) ;
 EIN_EXPORT BOOL __stdcall EgtRemoveRawPart( int nRawId) ;
 EIN_EXPORT BOOL __stdcall EgtMoveToCornerRawPart( int nRawId, const double ptCorner[3], int nFlag) ;
@@ -573,6 +574,7 @@ EIN_EXPORT BOOL __stdcall EgtShowOnlyTable( bool bVal) ;
 EIN_EXPORT int  __stdcall EgtAddFixture( const wchar_t* wsName, const double ptPos[3], double dAngRotDeg, double dMov) ;
 EIN_EXPORT BOOL __stdcall EgtKeepFixture( int nFxtId, int nSouPhase) ;
 EIN_EXPORT BOOL __stdcall EgtRemoveFixture( int nFxtId) ;
+EIN_EXPORT BOOL __stdcall EgtVerifyFixture( int nFxtId) ;
 EIN_EXPORT int  __stdcall EgtGetFirstFixture( void) ;
 EIN_EXPORT int  __stdcall EgtGetNextFixture( int nFxtId) ;
 EIN_EXPORT BOOL __stdcall EgtMoveFixture( int nFxtId, const double vtMove[3]) ;
@@ -727,6 +729,7 @@ EIN_EXPORT BOOL __stdcall EgtGetGraphicSnapPoint( int nSnap, int nWinX, int nWin
 EIN_EXPORT BOOL __stdcall EgtGetGridSnapPointZ( BOOL bSketch, int nWinX, int nWinY, const double ptGrid[3], double ptP[3]) ;
 EIN_EXPORT int  __stdcall EgtGetLastSnapId( void) ;
 EIN_EXPORT BOOL __stdcall EgtGetLastSnapDir( double vtV[3]) ;
+EIN_EXPORT BOOL __stdcall EgtGetPlaneSnapPoint( int nWinX, int nWinY, const double vtN[3], double dDist, double ptP[3]) ;
 EIN_EXPORT BOOL __stdcall EgtSetShowMode( int nShowMode, BOOL bRedraw) ;
 EIN_EXPORT int  __stdcall EgtGetShowMode( void) ;
 EIN_EXPORT BOOL __stdcall EgtSetShowCurveDirection( BOOL bShow, BOOL bRedraw) ;
diff --git a/EMkMachMgr.h b/EMkMachMgr.h
index 75ce7e1..3006455 100644
--- a/EMkMachMgr.h
+++ b/EMkMachMgr.h
@@ -92,6 +92,7 @@ class __declspec( novtable) IMachMgr
       virtual int  AddFixture( const std::string& sName, const Point3d& ptPos, double dAngRotDeg, double dMov) = 0 ;
       virtual bool KeepFixture( int nFxtId, int nSouPhase) = 0 ;
       virtual bool RemoveFixture( int nFxtId) = 0 ;
+      virtual bool VerifyFixture( int nFxtId) const = 0 ;
       virtual int  GetFirstFixture( void) = 0 ;
       virtual int  GetNextFixture( int nFxtId) = 0 ;
       virtual bool MoveFixture( int nId, const Vector3d& vtMove) = 0 ;
diff --git a/EXeExecutor.h b/EXeExecutor.h
index b7bbda5..4cd98af 100644
--- a/EXeExecutor.h
+++ b/EXeExecutor.h
@@ -595,6 +595,7 @@ EXE_EXPORT bool ExeModifyRawPartSize( int nRawId, double dLength, double dWidth,
 EXE_EXPORT bool ExeModifyRawPartHeight( int nRawId, double dHeight) ;
 EXE_EXPORT bool ExeKeepRawPart( int nRawId, int nSouPhase) ;
 EXE_EXPORT bool ExeVerifyRawPartPhase( int nRawId, int nPhase) ;
+EXE_EXPORT bool ExeVerifyRawPartCurrPhase( int nRawId) ;
 EXE_EXPORT bool ExeRemoveRawPartFromCurrPhase( int nRawId) ;
 EXE_EXPORT bool ExeRemoveRawPart( int nRawId) ;
 EXE_EXPORT bool ExeRotateRawPart( int nRawId, const Vector3d& vtAx, double dAngRotDeg) ;
@@ -619,6 +620,7 @@ EXE_EXPORT bool ExeShowOnlyTable( bool bVal) ;
 EXE_EXPORT int  ExeAddFixture( const std::string& sName, const Point3d& ptPos, double dAngRotDeg, double dMov) ;
 EXE_EXPORT bool ExeKeepFixture( int nFxtId, int nSouPhase) ;
 EXE_EXPORT bool ExeRemoveFixture( int nFxtId) ;
+EXE_EXPORT bool ExeVerifyFixture( int nFxtId) ;
 EXE_EXPORT int  ExeGetFirstFixture( void) ;
 EXE_EXPORT int  ExeGetNextFixture( int nFxtId) ;
 EXE_EXPORT bool ExeMoveFixture( int nFxtId, const Vector3d& vtMove) ;
@@ -787,6 +789,7 @@ EXE_EXPORT bool ExeGetGraphicSnapPoint( int nSnap, int nWinX, int nWinY, int nSe
 EXE_EXPORT bool ExeGetGridSnapPointZ( bool bSketch, int nWinX, int nWinY, const Point3d& ptGrid, Point3d& ptP) ;
 EXE_EXPORT int  ExeGetLastSnapId( void) ;
 EXE_EXPORT bool ExeGetLastSnapDir( Vector3d& vtV) ;
+EXE_EXPORT bool ExeGetPlaneSnapPoint( int nWinX, int nWinY, const Plane3d& Plane, Point3d& ptP) ;
 EXE_EXPORT bool ExeSetShowMode( int nShowMode, bool bRedraw) ;
 EXE_EXPORT int  ExeGetShowMode( void) ;
 EXE_EXPORT bool ExeSetShowCurveDirection( bool bShow, bool bRedraw) ;