1 files changed, 50 insertions, 16 deletions

diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSDynamics.cs b/OpenSim/Region/Physics/BulletSPlugin/BSDynamics.cs
index 311cf4f..07e87d1 100644
--- a/OpenSim/Region/Physics/BulletSPlugin/BSDynamics.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSDynamics.cs
@@ -209,7 +209,7 @@ namespace OpenSim.Region.Physics.BulletSPlugin
                     m_VhoverTimescale = Math.Max(pValue, 0.01f);
                     break;
                 case Vehicle.LINEAR_DEFLECTION_EFFICIENCY:
-                    m_linearDeflectionEfficiency = Math.Max(pValue, 0.01f);
+                    m_linearDeflectionEfficiency = ClampInRange(0f, pValue, 1f);
                     break;
                 case Vehicle.LINEAR_DEFLECTION_TIMESCALE:
                     m_linearDeflectionTimescale = Math.Max(pValue, 0.01f);
@@ -707,7 +707,6 @@ namespace OpenSim.Region.Physics.BulletSPlugin
         private Vector3 m_knownRotationalVelocity;
         private Vector3 m_knownRotationalForce;
         private Vector3 m_knownRotationalImpulse;
-        private Vector3 m_knownForwardVelocity;    // vehicle relative forward speed
 
         private const int m_knownChangedPosition           = 1 << 0;
         private const int m_knownChangedVelocity           = 1 << 1;
@@ -719,7 +718,6 @@ namespace OpenSim.Region.Physics.BulletSPlugin
         private const int m_knownChangedRotationalImpulse  = 1 << 7;
         private const int m_knownChangedTerrainHeight      = 1 << 8;
         private const int m_knownChangedWaterLevel         = 1 << 9;
-        private const int m_knownChangedForwardVelocity    = 1 <<10;
 
         public void ForgetKnownVehicleProperties()
         {
@@ -923,12 +921,7 @@ namespace OpenSim.Region.Physics.BulletSPlugin
         {
             get
             {
-                if ((m_knownHas & m_knownChangedForwardVelocity) == 0)
-                {
-                    m_knownForwardVelocity = VehicleVelocity * Quaternion.Inverse(Quaternion.Normalize(VehicleOrientation));
-                    m_knownHas |= m_knownChangedForwardVelocity;
-                }
-                return m_knownForwardVelocity;
+                return VehicleVelocity * Quaternion.Inverse(Quaternion.Normalize(VehicleOrientation));
             }
         }
         private float VehicleForwardSpeed
@@ -981,6 +974,8 @@ namespace OpenSim.Region.Physics.BulletSPlugin
         {
             ComputeLinearVelocity(pTimestep);
 
+            ComputeLinearDeflection(pTimestep);
+
             ComputeLinearTerrainHeightCorrection(pTimestep);
 
             ComputeLinearHover(pTimestep);
@@ -1026,12 +1021,12 @@ namespace OpenSim.Region.Physics.BulletSPlugin
         {
             // Step the motor from the current value. Get the correction needed this step.
             Vector3 origVelW = VehicleVelocity;             // DEBUG
-            Vector3 currentVelV = VehicleVelocity * Quaternion.Inverse(VehicleOrientation);
+            Vector3 currentVelV = VehicleForwardVelocity;
             Vector3 linearMotorCorrectionV = m_linearMotor.Step(pTimestep, currentVelV);
 
-            // Friction reduces vehicle motion
-            Vector3 frictionFactorW = ComputeFrictionFactor(m_linearFrictionTimescale, pTimestep);
-            linearMotorCorrectionV -= (currentVelV * frictionFactorW);
+            // Friction reduces vehicle motion based on absolute speed. Slow vehicle down by friction.
+            Vector3 frictionFactorV = ComputeFrictionFactor(m_linearFrictionTimescale, pTimestep);
+            linearMotorCorrectionV -= (currentVelV * frictionFactorV);
 
             // Motor is vehicle coordinates. Rotate it to world coordinates
             Vector3 linearMotorVelocityW = linearMotorCorrectionV * VehicleOrientation;
@@ -1046,11 +1041,38 @@ namespace OpenSim.Region.Physics.BulletSPlugin
             // Add this correction to the velocity to make it faster/slower.
             VehicleVelocity += linearMotorVelocityW;
 
-
-
             VDetailLog("{0},  MoveLinear,velocity,origVelW={1},velV={2},correctV={3},correctW={4},newVelW={5},fricFact={6}",
                         ControllingPrim.LocalID, origVelW, currentVelV, linearMotorCorrectionV,
-                        linearMotorVelocityW, VehicleVelocity, frictionFactorW);
+                        linearMotorVelocityW, VehicleVelocity, frictionFactorV);
+        }
+
+        //Given a Deflection Effiency and a Velocity, Returns a Velocity that is Partially Deflected onto the X Axis
+        //Clamped so that a DeflectionTimescale of less then 1 does not increase force over original velocity
+        private void ComputeLinearDeflection(float pTimestep)
+        {
+            Vector3 linearDeflectionV = Vector3.Zero;
+            Vector3 velocityV = VehicleForwardVelocity;
+
+            // Velocity in Y and Z dimensions is movement to the side or turning.
+            // Compute deflection factor from the to the side and rotational velocity
+            linearDeflectionV.Y = SortedClampInRange(0, (velocityV.Y * m_linearDeflectionEfficiency) / m_linearDeflectionTimescale, velocityV.Y);
+            linearDeflectionV.Z = SortedClampInRange(0, (velocityV.Z * m_linearDeflectionEfficiency) / m_linearDeflectionTimescale, velocityV.Z);
+
+            // Velocity to the side and around is corrected and moved into the forward direction
+            linearDeflectionV.X += Math.Abs(linearDeflectionV.Y);
+            linearDeflectionV.X += Math.Abs(linearDeflectionV.Z);
+
+            // Scale the deflection to the fractional simulation time
+            linearDeflectionV *= pTimestep;
+
+            // Subtract the sideways and rotational velocity deflection factors while adding the correction forward
+            linearDeflectionV *= new Vector3(1,-1,-1);
+
+            // Correciont is vehicle relative. Convert to world coordinates and add to the velocity
+            VehicleVelocity += linearDeflectionV * VehicleOrientation;
+
+            VDetailLog("{0},  MoveLinear,LinearDeflection,linDefEff={1},linDefTS={2},linDeflectionV={3}",
+                        ControllingPrim.LocalID, m_linearDeflectionEfficiency, m_linearDeflectionTimescale, linearDeflectionV);
         }
 
         public void ComputeLinearTerrainHeightCorrection(float pTimestep)
@@ -1652,6 +1674,18 @@ namespace OpenSim.Region.Physics.BulletSPlugin
             return frictionFactor;
         }
 
+        private float SortedClampInRange(float clampa, float val, float clampb)
+        {
+            if (clampa > clampb)
+            {
+                float temp = clampa;
+                clampa = clampb;
+                clampb = temp;
+            }
+           return ClampInRange(clampa, val, clampb);
+
+        }
+
         private float ClampInRange(float low, float val, float high)
         {
             return Math.Max(low, Math.Min(val, high));