diff --git a/EXE_GdbModify.cpp b/EXE_GdbModify.cpp
index e0cb72a..4300f2d 100644
--- a/EXE_GdbModify.cpp
+++ b/EXE_GdbModify.cpp
@@ -98,6 +98,35 @@ ExeChangeVectorBase( int nId, const Point3d& ptB, int nRefType)
    return bOk ;
 }
 
+//----------------------------------------------------------------------------
+bool
+ExeInvertVector( const INTVECTOR& vIds)
+{
+   IGeomDB* pGeomDB = GetCurrGeomDB() ;
+   VERIFY_GEOMDB( pGeomDB, false)
+  // eseguo inversione
+   bool bOk = true ;
+   for ( size_t i = 0 ; i < vIds.size() && bOk ; ++ i) {
+      int nId = (( vIds[i] != GDB_ID_SEL) ? vIds[i] : pGeomDB->GetFirstSelectedObj()) ;
+      while ( nId != GDB_ID_NULL  &&  bOk) {
+        // recupero il vettore e lo inverto
+         IGeoVector3d* pGVect = GetGeoVector3d( pGeomDB->GetGeoObj( nId)) ;
+         bOk = ( pGVect != nullptr  &&  pGVect->ChangeVector( - pGVect->GetVector())) ;
+        // passo alla successiva
+         nId = (( vIds[i] != GDB_ID_SEL) ? GDB_ID_NULL : pGeomDB->GetNextSelectedObj()) ;
+      }
+   }
+   ExeSetModified() ;
+  // se richiesto, salvo il comando Lua equivalente
+   if ( IsCmdLog()) {
+      string sLua = "EgtInvertVector({" + IdListToString( vIds) + "})" +
+                    " -- Ok=" + ToString( bOk) ;
+      LOG_INFO( GetCmdLogger(), sLua.c_str()) ;
+   }
+  // restituisco risultato
+   return bOk ;
+}
+
 //-------------------------------------------------------------------------------
 bool
 ExeModifyText( int nId, const string& sNewText)
diff --git a/EXE_GdbModifyCurve.cpp b/EXE_GdbModifyCurve.cpp
index a7d4ecd..89785c5 100644
--- a/EXE_GdbModifyCurve.cpp
+++ b/EXE_GdbModifyCurve.cpp
@@ -53,8 +53,7 @@ ExeInvertCurve( const INTVECTOR& vIds)
       while ( nId != GDB_ID_NULL  &&  bOk) {
         // recupero la curva e la inverto
          ICurve* pCurve = GetCurve( pGeomDB->GetGeoObj( nId)) ;
-         if ( pCurve != nullptr  &&  ! pCurve->Invert())
-            bOk = false ;
+         bOk = ( pCurve != nullptr  &&  pCurve->Invert()) ;
         // passo alla successiva
          nId = (( vIds[i] != GDB_ID_SEL) ? GDB_ID_NULL : pGeomDB->GetNextSelectedObj()) ;
       }
diff --git a/EXE_GeomDB.cpp b/EXE_GeomDB.cpp
index e8851c4..9e7a2c8 100644
--- a/EXE_GeomDB.cpp
+++ b/EXE_GeomDB.cpp
@@ -52,7 +52,7 @@ ExeInitContext( void)
 }
 
 //-----------------------------------------------------------------------------
-int
+bool
 ExeDeleteContext( int nGseCtx)
 {
   // se contesto corrente, lo resetto
diff --git a/EgtExecutor.rc b/EgtExecutor.rc
index ae4e384..0fc7f19 100644
Binary files a/EgtExecutor.rc and b/EgtExecutor.rc differ
diff --git a/LUA_GdbModify.cpp b/LUA_GdbModify.cpp
index d0458c5..e0cc7c1 100644
--- a/LUA_GdbModify.cpp
+++ b/LUA_GdbModify.cpp
@@ -58,6 +58,21 @@ LuaChangeVectorBase( lua_State* L)
    return 1 ;
 }
 
+//----------------------------------------------------------------------------
+static int
+LuaInvertVector( lua_State* L)
+{
+  // 1 parametro : Id/s
+   INTVECTOR vId ;
+   LuaCheckParam( L, 1, vId)
+   LuaClearStack( L) ;
+  // eseguo inversione vettori
+   bool bOk = ExeInvertVector( vId) ;
+  // restituisco il risultato
+   LuaSetParam( L, bOk) ;
+   return 1 ;
+}
+
 //-------------------------------------------------------------------------------
 static int
 LuaModifyText( lua_State* L)
@@ -165,6 +180,7 @@ LuaInstallGdbModify( LuaMgr& luaMgr)
    bool bOk = ( &luaMgr != nullptr) ;
    bOk = bOk && luaMgr.RegisterFunction( "EgtChangeGroupFrame", LuaChangeGroupFrame) ;
    bOk = bOk && luaMgr.RegisterFunction( "EgtChangeVectorBase", LuaChangeVectorBase) ;
+   bOk = bOk && luaMgr.RegisterFunction( "EgtInvertVector", LuaInvertVector) ;
    bOk = bOk && luaMgr.RegisterFunction( "EgtModifyText", LuaModifyText) ;
    bOk = bOk && luaMgr.RegisterFunction( "EgtChangeTextFont", LuaChangeTextFont) ;
    bOk = bOk && luaMgr.RegisterFunction( "EgtFlipText", LuaFlipText) ;
diff --git a/LUA_General.cpp b/LUA_General.cpp
index b870314..2d790be 100644
--- a/LUA_General.cpp
+++ b/LUA_General.cpp
@@ -74,32 +74,6 @@ LuaEvalNumExpr( lua_State* L)
    return 1 ;
 }
 
-//-------------------------------------------------------------------------------
-static int
-LuaSetContext( lua_State* L)
-{
-  // un solo parametro intero
-   int nGseCtx ;
-   LuaCheckParam( L, 1, nGseCtx)
-   LuaClearStack( L) ;
-  // imposto il contesto
-   bool bOk = SetCurrGseContext( nGseCtx) ;
-  // restituisco il risultato
-   LuaSetParam( L, bOk) ;
-   return 1 ;
-}
-
-//-------------------------------------------------------------------------------
-static int
-LuaGetContext( lua_State* L)
-{
-  // nessun parametro
-   LuaClearStack( L) ;
-  // restituisco l'indice del contesto
-   LuaSetParam( L, GetIndCurrGseContext()) ;
-   return 1 ;
-}
-
 //-------------------------------------------------------------------------------
 static int
 LuaPause( lua_State* L)
@@ -170,8 +144,7 @@ LuaSplitString( lua_State* L)
    string sVal ;
    string sSep = "," ;
    bool bFound = LuaGetParam( L, 1, sVal) ;
-   if ( bFound)
-      LuaGetParam( L, 2, sSep) ;
+   LuaGetParam( L, 2, sSep) ;
    LuaClearStack( L) ;
   // se ricevuta stringa, la divido in parti separate da ','
    if ( bFound) {
@@ -186,6 +159,29 @@ LuaSplitString( lua_State* L)
    return 1 ;
 }
 
+//-------------------------------------------------------------------------------
+static int
+LuaSplitStringPlus( lua_State* L)
+{
+  // 2 parametri : sVal, sHea
+   string sVal ;
+   string sHea ;
+   bool bFound = LuaGetParam( L, 1, sVal) ;
+   LuaCheckParam( L, 2, sHea)
+   LuaClearStack( L) ;
+  // se ricevuta stringa, la divido in parti conservandone le intestazioni
+   if ( bFound) {
+      STRVECTOR vsVal ;
+      TokenizePlus( sVal, sHea, vsVal) ;
+     // ritorno il risultato
+      LuaSetParam( L, vsVal) ;
+   }
+  // altrimenti restituisco nil
+   else
+      LuaSetParam( L) ;
+   return 1 ;
+}
+
 //-------------------------------------------------------------------------------
 static int
 LuaExecTsc( lua_State* L)
@@ -442,13 +438,12 @@ LuaInstallGeneral( LuaMgr& luaMgr)
    bool bOk = ( &luaMgr != nullptr) ;
    bOk = bOk && luaMgr.RegisterFunction( "print", MyPrint) ;
    bOk = bOk && luaMgr.RegisterFunction( "EgtEvalNumExpr", LuaEvalNumExpr) ;
-   bOk = bOk && luaMgr.RegisterFunction( "EgtSetContext", LuaSetContext) ;
-   bOk = bOk && luaMgr.RegisterFunction( "EgtGetContext", LuaGetContext) ;
    bOk = bOk && luaMgr.RegisterFunction( "EgtPause", LuaPause) ;
    bOk = bOk && luaMgr.RegisterFunction( "EgtStartCounter", LuaStartCounter) ;
    bOk = bOk && luaMgr.RegisterFunction( "EgtStopCounter", LuaStopCounter) ;
    bOk = bOk && luaMgr.RegisterFunction( "EgtNumToString", LuaNumToString) ;
    bOk = bOk && luaMgr.RegisterFunction( "EgtSplitString", LuaSplitString) ;
+   bOk = bOk && luaMgr.RegisterFunction( "EgtSplitStringPlus", LuaSplitStringPlus) ;
    bOk = bOk && luaMgr.RegisterFunction( "EgtExecTsc", LuaExecTsc) ;
    bOk = bOk && luaMgr.RegisterFunction( "EgtOutLog", LuaOutLog) ;
    bOk = bOk && luaMgr.RegisterFunction( "EgtOutBox", LuaOutBox) ;
diff --git a/LUA_GeomDB.cpp b/LUA_GeomDB.cpp
index a5c7d0b..0748069 100644
--- a/LUA_GeomDB.cpp
+++ b/LUA_GeomDB.cpp
@@ -13,6 +13,7 @@
 
 //--------------------------- Include ----------------------------------------
 #include "stdafx.h"
+#include "EXE.h"
 #include "LUA.h"
 #include "/EgtDev/Include/EXeExecutor.h"
 #include "/EgtDev/Include/EGkGdbConst.h"
@@ -21,6 +22,71 @@
 using namespace std ;
 
 
+//-------------------------------------------------------------------------------
+static int
+LuaCreateContext( lua_State* L)
+{
+  // nessun parametro
+   LuaClearStack( L) ;
+  // creo il contesto (senza grafica)
+   int nCtx = ExeInitContext() ;
+  // restituisco il risultato
+   if ( nCtx != 0)
+      LuaSetParam( L, nCtx) ;
+   else
+      LuaSetParam( L) ;
+   return 1 ;
+}
+
+//-------------------------------------------------------------------------------
+static int
+LuaSetContext( lua_State* L)
+{
+  // un solo parametro intero
+   int nGseCtx ;
+   LuaCheckParam( L, 1, nGseCtx)
+   LuaClearStack( L) ;
+  // imposto il contesto
+   bool bOk = ExeSetCurrentContext( nGseCtx) ;
+  // restituisco il risultato
+   LuaSetParam( L, bOk) ;
+   return 1 ;
+}
+
+//-------------------------------------------------------------------------------
+static int
+LuaGetContext( lua_State* L)
+{
+  // nessun parametro
+   LuaClearStack( L) ;
+  // recupero il contesto corrente
+   int nCtx = ExeGetCurrentContext() ;
+  // restituisco il risultato
+   if ( nCtx != 0)
+      LuaSetParam( L, nCtx) ;
+   else
+      LuaSetParam( L) ;
+   return 1 ;
+}
+
+//-------------------------------------------------------------------------------
+static int
+LuaDeleteContext( lua_State* L)
+{
+  // un solo parametro intero
+   int nGseCtx ;
+   LuaCheckParam( L, 1, nGseCtx)
+   LuaClearStack( L) ;
+  // posso cancellare solo contesti senza grafica (con lua si possono creare solo cosė)
+   GseContext* pGseCtx = GetGseContext( nGseCtx) ;
+   bool bOk = false ;
+   if ( pGseCtx != nullptr  &&  pGseCtx->m_pScene == nullptr)
+      bOk = ExeDeleteContext( nGseCtx) ;
+  // restituisco il risultato
+   LuaSetParam( L, bOk) ;
+   return 1 ;
+}
+
 //-------------------------------------------------------------------------------
 static int
 LuaSetDefaultMaterial( lua_State* L)
@@ -232,6 +298,10 @@ bool
 LuaInstallGeomDB( LuaMgr& luaMgr)
 {
    bool bOk = ( &luaMgr != nullptr) ;
+   bOk = bOk && luaMgr.RegisterFunction( "EgtCreateContext", LuaCreateContext) ;
+   bOk = bOk && luaMgr.RegisterFunction( "EgtSetContext", LuaSetContext) ;
+   bOk = bOk && luaMgr.RegisterFunction( "EgtGetContext", LuaGetContext) ;
+   bOk = bOk && luaMgr.RegisterFunction( "EgtDeleteContext", LuaDeleteContext) ;
    bOk = bOk && luaMgr.RegisterFunction( "EgtSetDefaultMaterial", LuaSetDefaultMaterial) ;
    bOk = bOk && luaMgr.RegisterFunction( "EgtSetGridFrame", LuaSetGridFrame) ;
    bOk = bOk && luaMgr.RegisterFunction( "EgtGetGridFrame", LuaGetGridFrame) ;