When calling osNpcMoveTo(), rotate the avatar in the direction of travel.

This stops the npc walking backwards if the target is directly behind.
This means that the npc no longer returns to its original rotation once movement has finished.
If you want this behaviour, please store and reset the original rotation after movement.
This is somewhat to address http://opensimulator.org/mantis/view.php?id=5678

2 files changed, 33 insertions, 6 deletions

diff --git a/OpenSim/Region/Framework/Scenes/ScenePresence.cs b/OpenSim/Region/Framework/Scenes/ScenePresence.cs
index 9358a4a..cd3cb60 100644
--- a/OpenSim/Region/Framework/Scenes/ScenePresence.cs
+++ b/OpenSim/Region/Framework/Scenes/ScenePresence.cs
@@ -585,7 +585,11 @@ namespace OpenSim.Region.Framework.Scenes
         public Quaternion Rotation
         {
             get { return m_bodyRot; }
-            set { m_bodyRot = value; }
+            set
+            {
+                m_bodyRot = value;
+                m_log.DebugFormat("[SCENE PRESENCE]: Body rot for {0} set to {1}", Name, m_bodyRot);
+            }
         }
 
         public Quaternion PreviousRotation
@@ -1711,7 +1715,7 @@ namespace OpenSim.Region.Framework.Scenes
 
             // Fudge factor.  It appears that if one clicks "go here" on a piece of ground, the go here request is
             // always slightly higher than the actual terrain height.
-            // FIXME: This constrains NOC movements as well, so should be somewhere else.
+            // FIXME: This constrains NPC movements as well, so should be somewhere else.
             if (pos.Z - terrainHeight < 0.2)
                 pos.Z = terrainHeight;
 
@@ -1727,6 +1731,21 @@ namespace OpenSim.Region.Framework.Scenes
             MovingToTarget = true;
             MoveToPositionTarget = pos;
 
+            // Rotate presence around the z-axis to point in same direction as movement.
+            // Ignore z component of vector
+            Vector3 localVectorToTarget3D = pos - AbsolutePosition;
+            Vector3 localVectorToTarget2D = new Vector3((float)(localVectorToTarget3D.X), (float)(localVectorToTarget3D.Y), 0f);
+
+//            m_log.DebugFormat("[SCENE PRESENCE]: Local vector to target is {0}", localVectorToTarget2D);
+
+            // Calculate the yaw.
+            Vector3 angle = new Vector3(0, 0, (float)(Math.Atan2(localVectorToTarget2D.Y, localVectorToTarget2D.X)));
+
+//            m_log.DebugFormat("[SCENE PRESENCE]: Angle is {0}", angle);
+
+            Rotation = Quaternion.CreateFromEulers(angle);
+//            m_log.DebugFormat("[SCENE PRESENCE]: Body rot for {0} set to {1}", Name, Rotation);
+
             Vector3 agent_control_v3 = new Vector3();
             HandleMoveToTargetUpdate(ref agent_control_v3);
             AddNewMovement(agent_control_v3);
diff --git a/OpenSim/Region/OptionalModules/World/NPC/Tests/NPCModuleTests.cs b/OpenSim/Region/OptionalModules/World/NPC/Tests/NPCModuleTests.cs
index 246bc34..1a0d0c7 100644
--- a/OpenSim/Region/OptionalModules/World/NPC/Tests/NPCModuleTests.cs
+++ b/OpenSim/Region/OptionalModules/World/NPC/Tests/NPCModuleTests.cs
@@ -182,18 +182,21 @@ namespace OpenSim.Region.OptionalModules.World.NPC.Tests
             scene.Update();
             Assert.That(npc.AbsolutePosition, Is.EqualTo(startPos));
 
-            Vector3 targetPos = startPos + new Vector3(0, 0, 10);
+            Vector3 targetPos = startPos + new Vector3(0, 10, 0);
             npcModule.MoveToTarget(npc.UUID, scene, targetPos, false, false);
 
             Assert.That(npc.AbsolutePosition, Is.EqualTo(startPos));
+            //Assert.That(npc.Rotation, Is.EqualTo(new Quaternion(0, 0, 0.7071068f, 0.7071068f)));
+            Assert.That(
+                npc.Rotation, new QuaternionToleranceConstraint(new Quaternion(0, 0, 0.7071068f, 0.7071068f), 0.000001));
 
             scene.Update();
 
             // We should really check the exact figure.
             Assert.That(npc.AbsolutePosition.X, Is.EqualTo(startPos.X));
-            Assert.That(npc.AbsolutePosition.Y, Is.EqualTo(startPos.Y));
-            Assert.That(npc.AbsolutePosition.Z, Is.GreaterThan(startPos.Z));
-            Assert.That(npc.AbsolutePosition.Z, Is.LessThan(targetPos.Z));
+            Assert.That(npc.AbsolutePosition.Y, Is.GreaterThan(startPos.Y));
+            Assert.That(npc.AbsolutePosition.Z, Is.EqualTo(startPos.Z));
+            Assert.That(npc.AbsolutePosition.Z, Is.LessThan(targetPos.X));
 
             for (int i = 0; i < 10; i++)
                 scene.Update();
@@ -208,6 +211,11 @@ namespace OpenSim.Region.OptionalModules.World.NPC.Tests
             targetPos = startPos + new Vector3(10, 0, 0);
             npcModule.MoveToTarget(npc.UUID, scene, targetPos, false, false);
 
+            Assert.That(npc.AbsolutePosition, Is.EqualTo(startPos));
+//            Assert.That(npc.Rotation, Is.EqualTo(new Quaternion(0, 0, 0, 1)));
+            Assert.That(
+                npc.Rotation, new QuaternionToleranceConstraint(new Quaternion(0, 0, 0, 1), 0.000001));
+
             scene.Update();
 
             // We should really check the exact figure.