diff --git a/Display.cpp b/Display.cpp
index f0f9bbe..efe368a 100644
--- a/Display.cpp
+++ b/Display.cpp
@@ -203,7 +203,7 @@ void Display::update ()
             {
                 std::cout << "## no more open lines -> fin!" << std::endl;
                 m_points.clear();
-                m_textStatus.setString(text + "finished calculating convex hull in " + std::to_string(m_step / 5) + " cycles");
+                if (m_points.size() == 0) m_textStatus.setString(text + "finished calculating convex hull in " + std::to_string((m_step / 4 + 1)) + " cycles");
                 return;
             }
 
@@ -290,7 +290,7 @@ void Display::update ()
         m_textStatus.setString(text + "remove inner points...");
 
         size_t lines = m_lines.size() - 1;
-        if (lines > 2)
+        if (lines > 0)
         {
             // assure clockwise order
             Point pt1 = m_lines[lines - 1].from();
@@ -326,7 +326,7 @@ void Display::update ()
         m_curLineIdx = -1;
         //m_curLine = m_lines[lines - 1];
 
-        if (m_points.size() == 0) m_textStatus.setString(text + "finished calculating convex hull in " + std::to_string(m_step/5) + " cycles");
+        if (m_points.size() == 0) m_textStatus.setString(text + "finished calculating convex hull in " + std::to_string((m_step / 4 + 1)) + " cycles");
         else m_textStatus.setString(text + "adding new hull point...");
     }
     else if (m_step > 0) m_textStatus.setString(text + "invalid status!");