diff --git a/vroni/Include/offset.h b/vroni/Include/offset.h
index 24274da..385e051 100644
--- a/vroni/Include/offset.h
+++ b/vroni/Include/offset.h
@@ -107,7 +107,7 @@ off_data* GetOffsetData(int i);
 { \
    cur_offset_list = num_offset_list;  \
    if (cur_offset_list >= max_num_offset_list) { \
-      max_num_offset_list += OFFS_HALF_BLOCK_SIZE; \
+      max_num_offset_list = ( cur_offset_list + 1) * 2 ; \
       gentlyResizeSTLVector(offset_list, max_num_offset_list, "offset:offset_list"); \
    } \
    ++num_offset_list; \
@@ -145,7 +145,7 @@ off_data* GetOffsetData(int i);
 #define StoreOffsetData(S, T, P) \
 { \
    if (num_offset_data >= max_num_offset_data) { \
-      max_num_offset_data += OFFS_BLOCK_SIZE; \
+      max_num_offset_data = ( num_offset_data + 1) * 2 ; \
       gentlyResizeSTLVector(offset_data, max_num_offset_data, "offset:offset_data"); \
    } \
    offset_data[num_offset_data].site = S; \
diff --git a/vroni/Include/stack.h b/vroni/Include/stack.h
index 053d1bc..5f01c59 100644
--- a/vroni/Include/stack.h
+++ b/vroni/Include/stack.h
@@ -27,7 +27,7 @@
 {\
     ++num_stack; \
     if (num_stack >= max_num_stack) { \
-       max_num_stack += STACK_INCR; \
+       max_num_stack = num_stack * 2 ; \
        stack = (STACK_TYPE*) ReallocateArray(stack, max_num_stack, sizeof(STACK_TYPE), STACK_STRING); \
     } \
     stack[num_stack] = data; \
diff --git a/vroni/Include/vd_data.h b/vroni/Include/vd_data.h
index c100617..8acf391 100644
--- a/vroni/Include/vd_data.h
+++ b/vroni/Include/vd_data.h
@@ -93,7 +93,7 @@ inline int vroniObject::GetLoopStackElementFunc(int I)
 #define PushOntoLoopStack(E) \
 {\
    if (num_loop_stack >= max_num_loop_stack) {  \
-      max_num_loop_stack += DATA_BLOCK_SIZE; \
+      max_num_loop_stack = ( num_loop_stack + 1) * 2; \
       loop_stack = (int*) ReallocateArray(loop_stack, max_num_loop_stack, \
                                           sizeof(int), "voronoi:loop_stack"); \
    } \
@@ -156,7 +156,7 @@ inline int vroniObject::GetLoopStackElementFunc(int I)
 #define AddToPreserveBuffer(S, T) \
 {\
    if (num_preserve >= max_num_preserve) {  \
-      max_num_preserve += DATA_BLOCK_SIZE; \
+      max_num_preserve = ( num_preserve + 1) * 2 ; \
       preserve = (preserve_buffer*) ReallocateArray(preserve, \
                                                     max_num_preserve, \
                                                     sizeof(preserve_buffer), \
@@ -172,7 +172,7 @@ inline int vroniObject::GetLoopStackElementFunc(int I)
 #define AddSiteVisited(I, T) \
 {\
    if (num_visited >= max_num_visited) { \
-   max_num_visited += DATA_BLOCK_SIZE; \
+   max_num_visited = ( num_visited + 1 ) * 2; \
    sites_visited = (s_visited*) ReallocateArray(sites_visited, \
                                                 max_num_visited, \
                                                 sizeof(s_visited), \
@@ -187,7 +187,7 @@ inline int vroniObject::GetLoopStackElementFunc(int I)
 #define AddPntVisited(I) \
 {\
    if (num_pnt_visited >= max_num_pnt_visited) { \
-   max_num_pnt_visited += DATA_BLOCK_SIZE; \
+   max_num_pnt_visited = ( num_pnt_visited + 1) * 2; \
    pnt_visited = (int*) ReallocateArray(pnt_visited, \
                                         max_num_pnt_visited, \
                                         sizeof(int), \
@@ -212,7 +212,7 @@ inline int vroniObject::GetLoopStackElementFunc(int I)
 #define AddNodeChecked(I) \
 {\
    if (num_checked >= max_num_checked) { \
-   max_num_checked += DATA_BLOCK_SIZE; \
+   max_num_checked = ( num_checked + 1) * 2; \
    nodes_checked = (int*) ReallocateArray(nodes_checked, \
                                           max_num_checked, \
                                           sizeof(int), \
diff --git a/vroni/Include/vroni_object.h b/vroni/Include/vroni_object.h
index d26239c..027348a 100644
--- a/vroni/Include/vroni_object.h
+++ b/vroni/Include/vroni_object.h
@@ -3107,6 +3107,11 @@ public :
    const char* GetExceptionMessage() ;
    int m_nMostViolatedRecursiveArcCount = 0 ;
 
+  // deallocazione memoria
+   void MyFreeVDConstructionData() ;
+   void apiFreeOffsetData() ;
+   void apiFreeBisectorBuffer() ;
+
  };
 
 
diff --git a/vroni/Lib/vroniD32.lib b/vroni/Lib/vroniD32.lib
index 39b74fc..fc2864b 100644
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diff --git a/vroni/Lib/vroniD32.pdb b/vroni/Lib/vroniD32.pdb
index e3f39e5..c0397bb 100644
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diff --git a/vroni/Lib/vroniD64.lib b/vroni/Lib/vroniD64.lib
index d901b0e..4dcf1b7 100644
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diff --git a/vroni/Lib/vroniR32.lib b/vroni/Lib/vroniR32.lib
index 1245282..0646188 100644
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diff --git a/vroni/Lib/vroniR64.lib b/vroni/Lib/vroniR64.lib
index d673434..bc4a85e 100644
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