--- a/src/node/random-walk-2d-mobility-model.cc	Thu Jul 19 09:48:10 2007 +0200
+++ b/src/node/random-walk-2d-mobility-model.cc	Thu Jul 19 09:54:57 2007 +0200
@@ -151,7 +151,20 @@
 void
 RandomWalk2dMobilityModel::Rebound (Time delayLeft)
 {
-  m_helper.Rebound (m_parameters->m_bounds);
+  Position position = m_helper.GetCurrentPosition (m_parameters->m_bounds);
+  Speed speed = m_helper.GetSpeed ();
+  switch (m_parameters->m_bounds.GetClosestSide (position))
+    {
+    case Rectangle::RIGHT:
+    case Rectangle::LEFT:
+      speed.dx = - speed.dx;
+      break;
+    case Rectangle::TOP:
+    case Rectangle::BOTTOM:
+      speed.dy = - speed.dy;
+      break;
+    }
+  m_helper.Reset (speed);
   DoWalk (delayLeft);
 }
 

--- a/src/node/static-speed-helper.cc	Thu Jul 19 09:48:10 2007 +0200
+++ b/src/node/static-speed-helper.cc	Thu Jul 19 09:54:57 2007 +0200
@@ -31,7 +31,7 @@
 }
 
 Speed 
-StaticSpeedHelper::GetCurrentSpeed (void) const
+StaticSpeedHelper::GetSpeed (void) const
 {
   return m_speed;
 }
@@ -80,25 +80,6 @@
   Time delay = Seconds ((nextPosition.x - m_position.x) / m_speed.dx);
   return delay;
 }
-void 
-StaticSpeedHelper::Rebound (const Rectangle &bounds)
-{
-  UpdateFull (bounds);
-  double xMinDist = m_position.x - bounds.xMin;
-  double xMaxDist = bounds.xMax - m_position.x;
-  double yMinDist = m_position.y - bounds.yMin;
-  double yMaxDist = bounds.yMax - m_position.y;
-  double minX = std::min (xMinDist, xMaxDist);
-  double minY = std::min (yMinDist, yMaxDist);
-  if (minY < minX)
-    {
-      m_speed.dy = - m_speed.dy;
-    }
-  else
-    {
-      m_speed.dx = - m_speed.dx;
-    }
-}
 
 void
 StaticSpeedHelper::UpdateFull (const Rectangle &bounds) const

--- a/src/node/static-speed-helper.h	Thu Jul 19 09:48:10 2007 +0200
+++ b/src/node/static-speed-helper.h	Thu Jul 19 09:54:57 2007 +0200
@@ -19,11 +19,10 @@
 
   void Reset (const Speed &speed);
   Time GetDelayToNextPosition (const Rectangle &bounds, Time delayLeft);
-  void Rebound (const Rectangle &bounds);
   Position GetCurrentPosition (const Rectangle &bounds) const;
 
   Position GetCurrentPosition (void) const;
-  Speed GetCurrentSpeed (void) const;
+  Speed GetSpeed (void) const;
 
  private:
   void Update (void) const;