diff --git a/EGkColor.h b/EGkColor.h
index f780159..8c3b563 100644
--- a/EGkColor.h
+++ b/EGkColor.h
@@ -15,12 +15,18 @@
 
 #include <stdlib.h>
 
+//-----------------------------------------------------------------------------
+static const int MAX_RGB = 255 ;
+static const int MAX_ALPHA = 100 ;
+static const float INV_MAX_RGB = 1 / float( MAX_RGB) ;
+static const float INV_MAX_ALPHA = 1 / float( MAX_ALPHA) ;
+
 //-----------------------------------------------------------------------------
 class Color
 {
    public :
       Color( void)
-             { m_Col[RED] = 0 ; m_Col[GREEN] = 0 ; m_Col[BLUE] = 0 ; m_Col[ALPHA] = 0 ; }
+             { m_Col[RED] = 0 ; m_Col[GREEN] = 0 ; m_Col[BLUE] = 0 ; m_Col[ALPHA] = MAX_ALPHA ; }
       Color( int nRed, int nGreen, int nBlue, int nAlpha = MAX_ALPHA)
             { Set( nRed, nGreen, nBlue, nAlpha) ; }
       Color( double dRed, double dGreen, double dBlue, double dAlpha = 1)
@@ -44,13 +50,13 @@ class Color
       int GetIntAlpha( void) const
             { return m_Col[ALPHA] ; }
       float GetRed( void) const
-            { return ( (float) m_Col[RED] / MAX_RGB) ; }
+            { return ( m_Col[RED] * INV_MAX_RGB) ; }
       float GetGreen( void) const
-            { return ( (float) m_Col[GREEN] / MAX_RGB) ; }
+            { return (  m_Col[GREEN] * INV_MAX_RGB) ; }
       float GetBlue( void) const
-            { return ( (float) m_Col[BLUE] / MAX_RGB) ; }
+            { return ( m_Col[BLUE] * INV_MAX_RGB) ; }
       float GetAlpha( void) const
-            { return ( (float) m_Col[ALPHA] / MAX_ALPHA) ; }
+            { return ( m_Col[ALPHA] * INV_MAX_ALPHA) ; }
       bool operator == ( const Color& other)
             { return ( m_Col[RED] == other.m_Col[RED] &&
                        m_Col[GREEN] == other.m_Col[GREEN] &&
@@ -59,9 +65,30 @@ class Color
 
    private :
       enum { RED = 0, GREEN = 1, BLUE = 2, ALPHA = 3, DIM = 4} ;
-      static const int MAX_RGB = 255 ;
-      static const int MAX_ALPHA = 100 ;
 
    private :
       unsigned char m_Col[DIM] ;
 } ;
+
+//----------------------------------------------------------------------------
+// Colori predefiniti
+//----------------------------------------------------------------------------
+const Color BLACK( 0, 0, 0) ;
+const Color GRAY( 128, 128, 128) ;
+const Color LGRAY( 192, 192, 192) ;
+const Color WHITE( 255, 255, 255) ;
+const Color RED( 255, 0, 0) ;
+const Color GREEN( 0, 255, 0) ;
+const Color BLUE( 0, 0, 255) ;
+const Color CYAN( 0, 255, 255) ;
+const Color MAGENTA( 255, 0, 255) ;
+const Color YELLOW( 255, 255, 0) ;
+const Color BROWN( 128, 64, 0) ;
+const Color PURPLE( 128, 0, 128) ;
+const Color ORANGE( 255, 128, 0) ;
+const Color LRED( 255, 128, 128) ;
+const Color LGREEN( 128, 255, 128) ;
+const Color LBLUE( 128, 128, 255) ;
+const Color LCYAN( 128, 255, 255) ;
+const Color LMAGENTA( 255, 128, 255) ;
+
diff --git a/EGkFrame3d.h b/EGkFrame3d.h
index ea5196d..7d3d8c0 100644
--- a/EGkFrame3d.h
+++ b/EGkFrame3d.h
@@ -36,6 +36,7 @@ class EGK_EXPORT Frame3d
       bool Set( const Point3d& ptOrig, const Vector3d& vtDirX, 
                 const Vector3d& vtDirY, const Vector3d& vtDirZ) ;
       bool Set( const Point3d& ptOrig, const Point3d& ptOnX, const Point3d& ptNearY) ;
+      bool Set( const Point3d& ptOrig, const Vector3d& vtDirZ) ;
       bool Set( const Point3d& ptOrig, Type nType) ;
       bool Reset( void) ;
       void Translate( const Vector3d& vtMove) ;
@@ -65,6 +66,7 @@ class EGK_EXPORT Frame3d
       bool GetRotationsCAC1( double& dAngC, double& dAngA, double& dAngC1) const ;
 
    private :
+      bool Verify( void) ;
       void CalculateType( void) ;
 
    private :
diff --git a/EGkGeoFrame3d.h b/EGkGeoFrame3d.h
index 08ee883..798a816 100644
--- a/EGkGeoFrame3d.h
+++ b/EGkGeoFrame3d.h
@@ -15,6 +15,8 @@
 
 #include "/EgtDev/Include/EGkGeoObj.h"
 
+class PolyLine ;
+
 //-----------------------------------------------------------------------------
 class __declspec( novtable) IGeoFrame3d : public IGeoObj
 {
@@ -23,6 +25,8 @@ class __declspec( novtable) IGeoFrame3d : public IGeoObj
                         const Vector3d& vtDirY, const Vector3d& vtDirZ) = 0 ;
       virtual bool Set( const Frame3d& frF) = 0 ;
       virtual const Frame3d& GetFrame( void) const = 0 ;
+      virtual bool GetDrawWithArrowHeads( double dLenA, double dFrazLenAH,
+                                          PolyLine& plX, PolyLine& plY, PolyLine& plZ) const = 0 ;
 } ;
 
 //-----------------------------------------------------------------------------
diff --git a/EGkGeoVector3d.h b/EGkGeoVector3d.h
index 05f8232..c392183 100644
--- a/EGkGeoVector3d.h
+++ b/EGkGeoVector3d.h
@@ -15,12 +15,15 @@
 
 #include "/EgtDev/Include/EGkGeoObj.h"
 
+class PolyLine ;
+
 //-----------------------------------------------------------------------------
 class __declspec( novtable) IGeoVector3d : public IGeoObj
 {
    public :
       virtual bool Set( const Vector3d& vtV) = 0 ;
       virtual const Vector3d& GetVector( void) const = 0 ;
+      virtual bool GetDrawWithArrowHead( double dFrazLenAH, PolyLine& PL) const = 0 ;
 } ;
 
 //-----------------------------------------------------------------------------