diff --git a/vroni/Include/mydefs.h b/vroni/Include/mydefs.h
index d652c96..ce40fe2 100644
--- a/vroni/Include/mydefs.h
+++ b/vroni/Include/mydefs.h
@@ -10,4 +10,5 @@
 #define MIC
 #define MAT
 #define EXT_APPL_PNTS
-#define EXT_APPL_SITES
\ No newline at end of file
+#define EXT_APPL_SITES
+#define GRAPHICS
\ No newline at end of file
diff --git a/vroni/Include/vddata.h b/vroni/Include/vddata.h
index f12e290..6804bfb 100644
--- a/vroni/Include/vddata.h
+++ b/vroni/Include/vddata.h
@@ -45,6 +45,7 @@ typedef enum {
    PARABOLA, 
    HYPERBOLA, 
    HYPERELL,
+   DEGENERATE_HYPERELL,
    NONE
 } BisectorType ;
 
diff --git a/vroni/Include/vroni_object.h b/vroni/Include/vroni_object.h
index 7daa4bf..87fe01a 100644
--- a/vroni/Include/vroni_object.h
+++ b/vroni/Include/vroni_object.h
@@ -1028,11 +1028,16 @@ public:
    int num_arc_buf, max_num_arc_buf;
    int num_vdn_buf, max_num_vdn_buf;
 
+   // MODIF : aggiunti dPar1 e dPar2
    struct vde_buffer
    {
       coord p1;  /* (x,y) coords of start point of a line seg  */
       coord p2;  /* (x,y) coords of end point of a line seg    */
       int color; /* color information; see defs.h              */
+
+      double dPar1; /* parametro sul bisettore a cui viene calcolato il punto p1 */
+      double dPar2; /* parametro sul bisettore a cui viene calcolato il punto p2 */
+
      //Ensure construction doesn't implicitly initialize elements - done explicitly later anyway
      inline vde_buffer() {}
    };            /* buffer for drawing edges of the VD         */
@@ -1343,9 +1348,12 @@ public:
    void ResetOffsetBuffer(void);
    void ResetCurBuffer(void);
    void ResetVDBuffer(void);
-   void UpdateBuffer(void);
+   void UpdateBuffer(void);   
    void AddEdgeToBuffer(double_arg x1, double_arg y1, 
                         double_arg x2, double_arg y2, int color);
+   // MODIF : aggiunta la funzione che gestisce anche i due parametri dPar1 e dPar2
+   void AddEdgeToBuffer(double_arg x1, double_arg y1, 
+                        double_arg x2, double_arg y2, int color, double dPar1, double dPar2);   
    void AddCirToBuffer(coord cntr, double_arg radius);
    void WriteIpeOutput(char *filename);
    void AddOffToBuffer(double_arg x1, double_arg y1, 
@@ -3082,10 +3090,11 @@ public :
 
   // voronoi
    void ResetVoronoiDiagram(void) ;
-   void GetVDBisectorPoints( int i, double ptS[3], double ptE[3]) ;
-   void GetVDBisectorParams( int i, double& dParS, double& dParE) ;
-   BisectorType GetVDBisectorType( int i) ;
-   void GetVDBisectorPointAtParam( int nEdge, double dPar, double pt[3]) ;
+   BisectorType GetBisectorType( int i) ;
+   int GetApproxedBisectorPointsNbr( int nEdge) ;
+   vr_bool GetApproxedBisectorPoint( int nEdge, int nPointIdx, double pt[3], double& dPar) ;
+   vr_bool GetDegenerateHyperEllipticBisectorData( int nEdge, double ptS[3], double ptE[3], double ptC[3], double& dParS, double& dParE) ;
+   vr_bool GetLinearBisectorData( int nEdge, double ptS[3], double ptE[3], double& dParS, double& dParE) ;
 
   // media axis
    vr_bool IsWMATEdge( int nEdge) ;
@@ -3093,6 +3102,8 @@ public :
   // debug
    void MyWriteVoronoiRegion( FILE *output) ;
 
+   int m_nBufferedVDEdge = -1 ;
+
  };
 
 
diff --git a/vroni/Lib/vroniD32.lib b/vroni/Lib/vroniD32.lib
index 99da55b..cce4c98 100644
Binary files a/vroni/Lib/vroniD32.lib and b/vroni/Lib/vroniD32.lib differ
diff --git a/vroni/Lib/vroniD64.lib b/vroni/Lib/vroniD64.lib
index fe4695d..7628ab5 100644
Binary files a/vroni/Lib/vroniD64.lib and b/vroni/Lib/vroniD64.lib differ
diff --git a/vroni/Lib/vroniR32.lib b/vroni/Lib/vroniR32.lib
index 4935e22..131bb17 100644
Binary files a/vroni/Lib/vroniR32.lib and b/vroni/Lib/vroniR32.lib differ
diff --git a/vroni/Lib/vroniR64.lib b/vroni/Lib/vroniR64.lib
index 923b22d..bf677cc 100644
Binary files a/vroni/Lib/vroniR64.lib and b/vroni/Lib/vroniR64.lib differ