--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/node/random-walk-position.cc	Mon Jul 02 14:07:51 2007 +0200
@@ -0,0 +1,153 @@
+/* -*-  Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil; -*- */
+/*
+ * Copyright (c) 2006,2007 INRIA
+ * All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation;
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ * Author: Mathieu Lacage <mathieu.lacage@sophia.inria.fr>
+ */
+#include "random-walk-position.h"
+#include "ns3/default-value.h"
+#include "ns3/time-default-value.h"
+#include "ns3/simulator.h"
+#include <cmath>
+
+namespace ns3 {
+
+static IntegerDefaultValue<double> g_minSpeed ("RandomWalkMinSpeed", 
+					       "Minimum speed used during a random walk", 
+					       0);
+static IntegerDefaultValue<double> g_maxSpeed ("RandomWalkMaxSpeed", 
+					       "Maximum speed used during a random walk",
+					       0);
+static EnumDefaultValue<RandomWalkPositionParameters::Mode> g_mode 
+  ("RandomWalkMode",
+   "The mode indicates the condition used to "
+   "change the current speed and direction",
+   RandomWalkPositionParameters::MODE_DISTANCE, "Distance",
+   RandomWalkPositionParameters::MODE_TIME, "Time",
+   0, 0);
+static IntegerDefaultValue<double> g_modeDistance ("RandomWalkModeDistance",
+						   "Distance to walk before changing direction and speed.",
+						   10);
+static TimeDefaultValue g_modeTime ("RandomWalkModeTime",
+				    "Time to walk before changing direction and speed.",
+				    Seconds (1));
+
+RandomWalkPositionParameters::RandomWalkPositionParameters ()
+  : m_minSpeed (g_minSpeed.GetValue ()),
+    m_maxSpeed (g_maxSpeed.GetValue ()),
+    m_mode (g_mode.GetValue ()),
+    m_modeDistance (g_modeDistance.GetValue ()),
+    m_modeTime (g_modeDistance.GetValue ())
+{}
+bool 
+RandomWalkPositionParameters::IsDefault (void) const
+{
+  if (m_minSpeed != g_minSpeed.GetValue () ||
+      m_maxSpeed != g_maxSpeed.GetValue () ||
+      m_mode != g_mode.GetValue () ||
+      m_modeDistance != g_modeDistance.GetValue () ||
+      m_modeTime != g_modeTime.GetValue ())
+    {
+      return false;
+    }
+  return true;
+}
+
+void
+RandomWalkPositionParameters::SetSpeedBounds (double minSpeed, double maxSpeed)
+{
+  m_minSpeed = minSpeed;
+  m_maxSpeed = maxSpeed;
+}
+
+
+UniformVariable RandomWalkPosition::m_randomDirection (0.0, 2*3.141592);
+
+Ptr<RandomWalkPositionParameters> 
+RandomWalkPosition::GetDefaultParameters (void)
+{
+  static Ptr<RandomWalkPositionParameters> parameters = Create<RandomWalkPositionParameters> ();
+  if (!parameters->IsDefault ())
+    {
+      parameters = Create<RandomWalkPositionParameters> ();
+    }
+  return parameters;
+}
+
+RandomWalkPosition::RandomWalkPosition ()
+  : m_x (0.0),
+    m_y (0.0),
+    m_dx (0.0),
+    m_dy (0.0),
+    m_prevTime (Simulator::Now ()),
+    m_parameters (RandomWalkPosition::GetDefaultParameters ())
+{
+  Reset ();
+}
+
+void
+RandomWalkPosition::Reset (void)
+{
+  Update ();
+  double speed = UniformVariable::GetSingleValue (m_parameters->m_minSpeed, 
+						  m_parameters->m_maxSpeed);
+  double direction = m_randomDirection.GetValue ();
+  double dx = std::cos (direction);
+  double dy = std::sin (direction);
+  m_dx = dx * speed;
+  m_dy = dy * speed;
+  Time delay;
+  if (m_parameters->m_mode == RandomWalkPositionParameters::MODE_TIME)
+    {
+      delay = m_parameters->m_modeTime;
+    }
+  else
+    {
+      double distance = g_modeDistance.GetValue ();
+      delay = Seconds (distance / sqrt (m_dx * m_dx + m_dy * m_dy));
+    }
+  Simulator::Schedule (delay, &RandomWalkPosition::Reset, this);
+}
+
+void
+RandomWalkPosition::Update (void) const
+{
+  Time deltaTime = Simulator::Now () - m_prevTime;
+  m_prevTime = Simulator::Now ();
+  double deltaS = deltaTime.GetSeconds ();
+  m_x += m_dx * deltaS;
+  m_y += m_dy * deltaS;
+}
+
+void 
+RandomWalkPosition::DoGet (double &x, double &y, double &z) const
+{
+  Update ();
+  x = m_x;
+  y = m_y;
+  z = 0;
+}
+void
+RandomWalkPosition::DoSet (double x, double y, double z)
+{
+  m_x = x;
+  m_y = y;
+  m_prevTime = Simulator::Now ();
+}
+
+
+} // namespace ns3