BulletSim: add BSVMotor as BSDynamics linear motor.

Properly limit *_MOTOR_DECAY_TIMESCALE to 120 as per specs.
Invode BSDynamics.Refresh() when vehicle type is changed. Previously
   the vehicle properties weren't getting set because the physical
   properties were set before the vehicle type was set.
Add a "use name" to BSMotors for identification while debugging.
Correct current and target confusion in BSVMotor design.
Rename CurrentValueReductionTimescale to FrictionTimescale.
Event more detailed logging.

2 files changed, 74 insertions, 27 deletions

diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSDynamics.cs b/OpenSim/Region/Physics/BulletSPlugin/BSDynamics.cs
index 7fd7b82..bf8a004 100644
--- a/OpenSim/Region/Physics/BulletSPlugin/BSDynamics.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSDynamics.cs
@@ -80,6 +80,7 @@ namespace OpenSim.Region.Physics.BulletSPlugin
         private Quaternion m_referenceFrame = Quaternion.Identity;
 
         // Linear properties
+        private BSVMotor m_linearMotor = new BSVMotor("LinearMotor");
         private Vector3 m_linearMotorDirection = Vector3.Zero;          // velocity requested by LSL, decayed by time
         private Vector3 m_linearMotorOffset = Vector3.Zero;             // the point of force can be offset from the center
         private Vector3 m_linearMotorDirectionLASTSET = Vector3.Zero;   // velocity requested by LSL
@@ -152,7 +153,7 @@ namespace OpenSim.Region.Physics.BulletSPlugin
                     m_angularDeflectionTimescale = Math.Max(pValue, 0.01f);
                     break;
                 case Vehicle.ANGULAR_MOTOR_DECAY_TIMESCALE:
-                    m_angularMotorDecayTimescale = Math.Max(pValue, 0.01f);
+                    m_angularMotorDecayTimescale = Math.Max(0.01f, Math.Min(pValue,120));
                     break;
                 case Vehicle.ANGULAR_MOTOR_TIMESCALE:
                     m_angularMotorTimescale = Math.Max(pValue, 0.01f);
@@ -185,10 +186,12 @@ namespace OpenSim.Region.Physics.BulletSPlugin
                     m_linearDeflectionTimescale = Math.Max(pValue, 0.01f);
                     break;
                 case Vehicle.LINEAR_MOTOR_DECAY_TIMESCALE:
-                    m_linearMotorDecayTimescale = Math.Max(pValue, 0.01f);
+                    m_linearMotorDecayTimescale = Math.Max(0.01f, Math.Min(pValue,120));
+                    m_linearMotor.TargetValueDecayTimeScale = m_linearMotorDecayTimescale;
                     break;
                 case Vehicle.LINEAR_MOTOR_TIMESCALE:
                     m_linearMotorTimescale = Math.Max(pValue, 0.01f);
+                    m_linearMotor.TimeScale = m_linearMotorTimescale;
                     break;
                 case Vehicle.VERTICAL_ATTRACTION_EFFICIENCY:
                     m_verticalAttractionEfficiency = Math.Max(0.1f, Math.Min(pValue, 1f));
@@ -208,10 +211,12 @@ namespace OpenSim.Region.Physics.BulletSPlugin
                     break;
                 case Vehicle.LINEAR_FRICTION_TIMESCALE:
                     m_linearFrictionTimescale = new Vector3(pValue, pValue, pValue);
+                    m_linearMotor.FrictionTimescale = m_linearFrictionTimescale;
                     break;
                 case Vehicle.LINEAR_MOTOR_DIRECTION:
                     m_linearMotorDirection = new Vector3(pValue, pValue, pValue);
                     m_linearMotorDirectionLASTSET = new Vector3(pValue, pValue, pValue);
+                    m_linearMotor.SetTarget(m_linearMotorDirection);
                     break;
                 case Vehicle.LINEAR_MOTOR_OFFSET:
                     m_linearMotorOffset = new Vector3(pValue, pValue, pValue);
@@ -238,10 +243,12 @@ namespace OpenSim.Region.Physics.BulletSPlugin
                     break;
                 case Vehicle.LINEAR_FRICTION_TIMESCALE:
                     m_linearFrictionTimescale = new Vector3(pValue.X, pValue.Y, pValue.Z);
+                    m_linearMotor.FrictionTimescale = m_linearFrictionTimescale;
                     break;
                 case Vehicle.LINEAR_MOTOR_DIRECTION:
                     m_linearMotorDirection = new Vector3(pValue.X, pValue.Y, pValue.Z);
                     m_linearMotorDirectionLASTSET = new Vector3(pValue.X, pValue.Y, pValue.Z);
+                    m_linearMotor.SetTarget(m_linearMotorDirection);
                     break;
                 case Vehicle.LINEAR_MOTOR_OFFSET:
                     m_linearMotorOffset = new Vector3(pValue.X, pValue.Y, pValue.Z);
@@ -319,6 +326,7 @@ namespace OpenSim.Region.Physics.BulletSPlugin
 
                     m_referenceFrame = Quaternion.Identity;
                     m_flags = (VehicleFlag)0;
+
                     break;
 
                 case Vehicle.TYPE_SLED:
@@ -510,6 +518,12 @@ namespace OpenSim.Region.Physics.BulletSPlugin
                                     | VehicleFlag.HOVER_GLOBAL_HEIGHT);
                     break;
             }
+
+            // Update any physical parameters based on this type.
+            Refresh();
+
+            m_linearMotor = new BSVMotor("LinearMotor", m_linearMotorTimescale, m_linearMotorDecayTimescale, m_linearFrictionTimescale, 1f);
+            m_linearMotor.PhysicsScene = PhysicsScene;  // DEBUG DEBUG DEBUG (enables detail logging)
         }
 
         // Some of the properties of this prim may have changed.
@@ -518,18 +532,25 @@ namespace OpenSim.Region.Physics.BulletSPlugin
         {
             if (IsActive)
             {
-                VDetailLog("{0},BSDynamics.Refresh", Prim.LocalID);
                 m_vehicleMass = Prim.Linkset.LinksetMass;
 
                 // Friction effects are handled by this vehicle code
-                BulletSimAPI.SetFriction2(Prim.PhysBody.ptr, 0f);
-                BulletSimAPI.SetHitFraction2(Prim.PhysBody.ptr, 0f);
-
-                BulletSimAPI.SetAngularDamping2(Prim.PhysBody.ptr, PhysicsScene.Params.vehicleAngularDamping);
-
-                BulletSimAPI.SetMassProps2(Prim.PhysBody.ptr, m_vehicleMass, new Vector3(1f, 1f, 1f));
-
-
+                float friction = 0f;
+                BulletSimAPI.SetFriction2(Prim.PhysBody.ptr, friction);
+
+                // Moderate angular movement introduced by Bullet.
+                // TODO: possibly set AngularFactor and LinearFactor for the type of vehicle.
+                //     Maybe compute linear and angular factor and damping from params.
+                float angularDamping = PhysicsScene.Params.vehicleAngularDamping;
+                BulletSimAPI.SetAngularDamping2(Prim.PhysBody.ptr, angularDamping);
+
+                // DEBUG DEBUG DEBUG: use uniform inertia to smooth movement added by Bullet
+                // Vector3 localInertia = new Vector3(1f, 1f, 1f);
+                Vector3 localInertia = new Vector3(m_vehicleMass, m_vehicleMass, m_vehicleMass);
+                BulletSimAPI.SetMassProps2(Prim.PhysBody.ptr, m_vehicleMass, localInertia);
+
+                VDetailLog("{0},BSDynamics.Refresh,frict={1},inert={2},aDamp={3}", 
+                                Prim.LocalID, friction, localInertia, angularDamping);
             }
         }
 
@@ -591,6 +612,7 @@ namespace OpenSim.Region.Physics.BulletSPlugin
         // Also does hover and float.
         private void MoveLinear(float pTimestep)
         {
+            /*
             // m_linearMotorDirection is the target direction we are moving relative to the vehicle coordinates
             // m_lastLinearVelocityVector is the current speed we are moving in that direction
             if (m_linearMotorDirection.LengthSquared() > 0.001f)
@@ -627,6 +649,12 @@ namespace OpenSim.Region.Physics.BulletSPlugin
 
                 VDetailLog("{0},MoveLinear,zeroed", Prim.LocalID);
             }
+            */
+
+            m_newVelocity = m_linearMotor.Step(pTimestep);
+
+            // Rotate new object velocity from vehicle relative to world coordinates
+            m_newVelocity *= Prim.ForceOrientation;
 
             // m_newVelocity is velocity computed from linear motor in world coordinates
 
@@ -785,12 +813,13 @@ namespace OpenSim.Region.Physics.BulletSPlugin
                 m_newVelocity.Z = 0;
 
             // Clamp REALLY high or low velocities
-            if (m_newVelocity.LengthSquared() > 1e6f)
+            float newVelocityLengthSq = m_newVelocity.LengthSquared();
+            if (newVelocityLengthSq > 1e6f)
             {
                 m_newVelocity /= m_newVelocity.Length();
                 m_newVelocity *= 1000f;
             }
-            else if (m_newVelocity.LengthSquared() < 1e-6f)
+            else if (newVelocityLengthSq < 1e-6f)
                 m_newVelocity = Vector3.Zero;
 
             // Stuff new linear velocity into the vehicle
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSMotors.cs b/OpenSim/Region/Physics/BulletSPlugin/BSMotors.cs
index b8bdd87..68eec2d 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BSMotors.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSMotors.cs
@@ -7,13 +7,15 @@ namespace OpenSim.Region.Physics.BulletSPlugin
 {
 public abstract class BSMotor
 {
-    public BSMotor()
+    public BSMotor(string useName)
     {
+        UseName = useName;
         PhysicsScene = null;
     }
     public virtual void Reset() { }
     public virtual void Zero() { }
 
+    public string UseName { get; private set; }
     // Used only for outputting debug information. Might not be set so check for null.
     public BSScene PhysicsScene { get; set; }
     protected void MDetailLog(string msg, params Object[] parms)
@@ -35,17 +37,25 @@ public class BSVMotor : BSMotor
 
     public float TimeScale { get; set; }
     public float TargetValueDecayTimeScale { get; set; }
-    public Vector3 CurrentValueReductionTimescale { get; set; }
+    public Vector3 FrictionTimescale { get; set; }
     public float Efficiency { get; set; }
 
     public Vector3 TargetValue { get; private set; }
     public Vector3 CurrentValue { get; private set; }
 
-    BSVMotor(float timeScale, float decayTimeScale, Vector3 frictionTimeScale, float efficiency) : base()
+    public BSVMotor(string useName)
+        : base(useName)
+    {
+        TimeScale = TargetValueDecayTimeScale = Efficiency = 1f;
+        FrictionTimescale = Vector3.Zero;
+        CurrentValue = TargetValue = Vector3.Zero;
+    }
+    public BSVMotor(string useName, float timeScale, float decayTimeScale, Vector3 frictionTimeScale, float efficiency) 
+        : this(useName)
     {
         TimeScale = timeScale;
         TargetValueDecayTimeScale = decayTimeScale;
-        CurrentValueReductionTimescale = frictionTimeScale;
+        FrictionTimescale = frictionTimeScale;
         Efficiency = efficiency;
         CurrentValue = TargetValue = Vector3.Zero;
     }
@@ -60,10 +70,10 @@ public class BSVMotor : BSMotor
     public Vector3 Step(float timeStep)
     {
         Vector3 returnCurrent = Vector3.Zero;
-        if (CurrentValue.LengthSquared() > 0.001f)
+        if (!CurrentValue.ApproxEquals(TargetValue, 0.01f))
         {
-            // Vector3 origDir = Target;       // DEBUG
-            // Vector3 origVel = CurrentValue;   // DEBUG
+            Vector3 origTarget = TargetValue;       // DEBUG
+            Vector3 origCurrVal = CurrentValue;   // DEBUG
 
             // Add (desiredVector - currentAppliedVector) / howLongItShouldTakeToComplete
             Vector3 addAmount = (TargetValue - CurrentValue)/TimeScale * timeStep;
@@ -74,11 +84,17 @@ public class BSVMotor : BSMotor
             float decayFactor = (1.0f / TargetValueDecayTimeScale) * timeStep;
             TargetValue *= (1f - decayFactor);
 
-            Vector3 frictionFactor = (Vector3.One / CurrentValueReductionTimescale) * timeStep;
+            Vector3 frictionFactor = Vector3.Zero;
+            frictionFactor = (Vector3.One / FrictionTimescale) * timeStep;
             CurrentValue *= (Vector3.One - frictionFactor);
 
-            MDetailLog("{0},BSVMotor.Step,nonZero,curr={1},target={2},add={3},decay={4},frict={5},ret={6}",
-                                    BSScene.DetailLogZero, TargetValue, CurrentValue, 
+            MDetailLog("{0},BSVMotor.Step,nonZero,{1},origTarget={2},origCurr={3},timeStep={4},timeScale={5},addAmnt={6},targetDecay={7},decayFact={8},fricTS={9},frictFact={10}",
+                                BSScene.DetailLogZero, UseName, origTarget, origCurrVal,
+                                timeStep, TimeScale, addAmount,
+                                TargetValueDecayTimeScale, decayFactor,
+                                FrictionTimescale, frictionFactor);
+            MDetailLog("{0},BSVMotor.Step,nonZero,{1},curr={2},target={3},add={4},decay={5},frict={6},ret={7}",
+                                    BSScene.DetailLogZero, UseName, TargetValue, CurrentValue, 
                                     addAmount, decayFactor, frictionFactor, returnCurrent);
         }
         else
@@ -87,8 +103,8 @@ public class BSVMotor : BSMotor
             CurrentValue = Vector3.Zero;
             TargetValue = Vector3.Zero;
 
-            MDetailLog("{0},BSVMotor.Step,zero,curr={1},target={2},ret={3}",
-                                    BSScene.DetailLogZero, TargetValue, CurrentValue, returnCurrent);
+            MDetailLog("{0},BSVMotor.Step,zero,{1},curr={2},target={3},ret={4}",
+                                    BSScene.DetailLogZero, UseName, TargetValue, CurrentValue, returnCurrent);
 
         }
         return returnCurrent;
@@ -105,7 +121,8 @@ public class BSFMotor : BSMotor
     public float Target { get; private set; }
     public float CurrentValue { get; private set; }
 
-    BSFMotor(float timeScale, float decayTimescale, float friction, float efficiency) : base()
+    public BSFMotor(string useName, float timeScale, float decayTimescale, float friction, float efficiency)
+        : base(useName)
     {
     }
     public void SetCurrent(float target)
@@ -122,7 +139,8 @@ public class BSFMotor : BSMotor
 public class BSPIDMotor : BSMotor
 {
     // TODO: write and use this one
-    BSPIDMotor() : base()
+    public BSPIDMotor(string useName)
+        : base(useName)
     {
     }
 }