BulletSim: Way too many changes in one commit.

Many changes to BSDynamic for readability and commentary.
Linkset hacking for vehicles: don't over mass the root prim.
Add parameter for link constraint solver iterations.
Correct uses of timestep in timescale calculations for vehicles.
Reorganize code/logic for making objects static and dynamic for readability
    and use of API2.
Changed most calls in BSPrim to use API2 calls (the new way).
Avatars do not generate default Bullet collision events but do call up
    to the simulator for every avatar. Reduces overhead.
Objects added to collision list only if they are processing collisions.
    Reduces overhead especially for large numbers of avatars.
Generalize call for water height to GetWaterHeightAtXYZ().
Catch and correct exception getting terrain height when out of bounds.
Correct race condition in Terrain Manager where creation wasn't at taint-time.
Add API calls for constructing compound shapes.
Move NeedsMeshing() logic into object class.
Reorganize logic for object meshing to reduce rebuilding of meshs/hulls.

1 files changed, 96 insertions, 122 deletions

diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSDynamics.cs b/OpenSim/Region/Physics/BulletSPlugin/BSDynamics.cs
index 8169e99..098fea7 100644
--- a/OpenSim/Region/Physics/BulletSPlugin/BSDynamics.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSDynamics.cs
@@ -80,7 +80,7 @@ namespace OpenSim.Region.Physics.BulletSPlugin
         // Linear properties
         private Vector3 m_linearMotorDirection = Vector3.Zero;          // velocity requested by LSL, decayed by time
         private Vector3 m_linearMotorDirectionLASTSET = Vector3.Zero;   // velocity requested by LSL
-        private Vector3 m_dir = Vector3.Zero;                           // velocity applied to body
+        private Vector3 m_newVelocity = Vector3.Zero;                   // velocity computed to be applied to body
         private Vector3 m_linearFrictionTimescale = Vector3.Zero;
         private float m_linearMotorDecayTimescale = 0;
         private float m_linearMotorTimescale = 0;
@@ -475,32 +475,33 @@ namespace OpenSim.Region.Physics.BulletSPlugin
                 frcount = 0;
 
             MoveLinear(pTimestep);
-            MoveAngular(pTimestep);
+            // MoveAngular(pTimestep);
             LimitRotation(pTimestep);
 
+            // remember the position so next step we can limit absolute movement effects
+            m_lastPositionVector = m_prim.Position;
+
             VDetailLog("{0},BSDynamics.Step,done,pos={1},force={2},velocity={3},angvel={4}", 
                     m_prim.LocalID, m_prim.Position, m_prim.Force, m_prim.Velocity, m_prim.RotationalVelocity);
         }// end Step
 
         private void MoveLinear(float pTimestep)
         {
-            // requested m_linearMotorDirection is significant
-            // if (!m_linearMotorDirection.ApproxEquals(Vector3.Zero, 0.01f))
-            if (m_linearMotorDirection.LengthSquared() > 0.0001f)
+            // m_linearMotorDirection is the direction we are moving relative to the vehicle coordinates
+            // m_lastLinearVelocityVector is the speed we are moving in that direction
+            if (m_linearMotorDirection.LengthSquared() > 0.001f)
             {
                 Vector3 origDir = m_linearMotorDirection;
                 Vector3 origVel = m_lastLinearVelocityVector;
 
                 // add drive to body
-                // Vector3 addAmount = m_linearMotorDirection/(m_linearMotorTimescale/pTimestep);
-                Vector3 addAmount = m_linearMotorDirection/(m_linearMotorTimescale);
-                // lastLinearVelocityVector is the current body velocity vector?
+                // Vector3 addAmount = m_linearMotorDirection/(m_linearMotorTimescale / pTimestep);
+                Vector3 addAmount = (m_linearMotorDirection - m_lastLinearVelocityVector)/(m_linearMotorTimescale / pTimestep);
+                // lastLinearVelocityVector is the current body velocity vector
                 // RA: Not sure what the *10 is for. A correction for pTimestep?
                 // m_lastLinearVelocityVector += (addAmount*10);  
                 m_lastLinearVelocityVector += addAmount;  
 
-                // This will work temporarily, but we really need to compare speed on an axis
-                // KF: Limit body velocity to applied velocity?
                 // Limit the velocity vector to less than the last set linear motor direction
                 if (Math.Abs(m_lastLinearVelocityVector.X) > Math.Abs(m_linearMotorDirectionLASTSET.X))
                     m_lastLinearVelocityVector.X = m_linearMotorDirectionLASTSET.X;
@@ -509,34 +510,29 @@ namespace OpenSim.Region.Physics.BulletSPlugin
                 if (Math.Abs(m_lastLinearVelocityVector.Z) > Math.Abs(m_linearMotorDirectionLASTSET.Z))
                     m_lastLinearVelocityVector.Z = m_linearMotorDirectionLASTSET.Z;
 
+                /*
                 // decay applied velocity
-                Vector3 decayfraction = ((Vector3.One/(m_linearMotorDecayTimescale/pTimestep)));
+                Vector3 decayfraction = Vector3.One/(m_linearMotorDecayTimescale / pTimestep);
+                // (RA: do not know where the 0.5f comes from)
                 m_linearMotorDirection -= m_linearMotorDirection * decayfraction * 0.5f;
-
-                /*
-                Vector3 addAmount = (m_linearMotorDirection - m_lastLinearVelocityVector)/m_linearMotorTimescale;
-                m_lastLinearVelocityVector += addAmount;
-
-                float decayfraction = (1.0f - 1.0f / m_linearMotorDecayTimescale);
-                m_linearMotorDirection *= decayfraction;
-
                  */
+                float keepfraction = 1.0f - (1.0f / (m_linearMotorDecayTimescale / pTimestep));
+                m_linearMotorDirection *= keepfraction;
 
-                VDetailLog("{0},MoveLinear,nonZero,origdir={1},origvel={2},add={3},decay={4},dir={5},vel={6}",
-                    m_prim.LocalID, origDir, origVel, addAmount, decayfraction, m_linearMotorDirection, m_lastLinearVelocityVector);
+                VDetailLog("{0},MoveLinear,nonZero,origdir={1},origvel={2},add={3},notDecay={4},dir={5},vel={6}",
+                    m_prim.LocalID, origDir, origVel, addAmount, keepfraction, m_linearMotorDirection, m_lastLinearVelocityVector);
             }
             else
             {
-                // if what remains of applied is small, zero it.
-                // if (m_lastLinearVelocityVector.ApproxEquals(Vector3.Zero, 0.01f))
-                //     m_lastLinearVelocityVector = Vector3.Zero;
+                // if what remains of direction is very small, zero it.
                 m_linearMotorDirection = Vector3.Zero;
                 m_lastLinearVelocityVector = Vector3.Zero;
+                VDetailLog("{0},MoveLinear,zeroed", m_prim.LocalID);
             }
 
             // convert requested object velocity to object relative vector
             Quaternion rotq = m_prim.Orientation;
-            m_dir = m_lastLinearVelocityVector * rotq;
+            m_newVelocity = m_lastLinearVelocityVector * rotq;
 
             // Add the various forces into m_dir which will be our new direction vector (velocity)
 
@@ -544,60 +540,31 @@ namespace OpenSim.Region.Physics.BulletSPlugin
             // KF: So far I have found no good method to combine a script-requested
             // .Z velocity and gravity. Therefore only 0g will used script-requested
             // .Z velocity. >0g (m_VehicleBuoyancy < 1) will used modified gravity only.
-            Vector3 grav = Vector3.Zero;
             // There is some gravity, make a gravity force vector that is applied after object velocity.
             // m_VehicleBuoyancy: -1=2g; 0=1g; 1=0g;
-            grav.Z = m_prim.Scene.DefaultGravity.Z * m_prim.Mass * (1f - m_VehicleBuoyancy);
+            Vector3 grav = m_prim.Scene.DefaultGravity * (m_prim.Mass * (1f - m_VehicleBuoyancy));
+
+            /*
+             * RA: Not sure why one would do this
             // Preserve the current Z velocity
             Vector3 vel_now = m_prim.Velocity;
             m_dir.Z = vel_now.Z;        // Preserve the accumulated falling velocity
+             */
 
             Vector3 pos = m_prim.Position;
-            Vector3 posChange = pos;
 //            Vector3 accel = new Vector3(-(m_dir.X - m_lastLinearVelocityVector.X / 0.1f), -(m_dir.Y - m_lastLinearVelocityVector.Y / 0.1f), m_dir.Z - m_lastLinearVelocityVector.Z / 0.1f);
-            double Zchange = Math.Abs(posChange.Z);
-            if (m_BlockingEndPoint != Vector3.Zero)
-            {
-                bool changed = false;
-                if (pos.X >= (m_BlockingEndPoint.X - (float)1))
-                {
-                    pos.X -= posChange.X + 1;
-                    changed = true;
-                }
-                if (pos.Y >= (m_BlockingEndPoint.Y - (float)1))
-                {
-                    pos.Y -= posChange.Y + 1;
-                    changed = true;
-                }
-                if (pos.Z >= (m_BlockingEndPoint.Z - (float)1))
-                {
-                    pos.Z -= posChange.Z + 1;
-                    changed = true;
-                }
-                if (pos.X <= 0)
-                {
-                    pos.X += posChange.X + 1;
-                    changed = true;
-                }
-                if (pos.Y <= 0)
-                {
-                    pos.Y += posChange.Y + 1;
-                    changed = true;
-                }
-                if (changed)
-                {
-                    m_prim.Position = pos;
-                    VDetailLog("{0},MoveLinear,blockingEndPoint,block={1},origPos={2},pos={3}",
-                                m_prim.LocalID, m_BlockingEndPoint, posChange, pos);
-                }
-            }
 
             // If below the terrain, move us above the ground a little.
-            if (pos.Z < m_prim.Scene.TerrainManager.GetTerrainHeightAtXYZ(pos))
+            float terrainHeight = m_prim.Scene.TerrainManager.GetTerrainHeightAtXYZ(pos);
+            // Taking the rotated size doesn't work here because m_prim.Size is the size of the root prim and not the linkset.
+            //     Need to add a m_prim.LinkSet.Size similar to m_prim.LinkSet.Mass.
+            // Vector3 rotatedSize = m_prim.Size * m_prim.Orientation;
+            // if (rotatedSize.Z < terrainHeight)
+            if (pos.Z < terrainHeight)
             {
-                pos.Z = m_prim.Scene.TerrainManager.GetTerrainHeightAtXYZ(pos) + 2;
+                pos.Z = terrainHeight + 2;
                 m_prim.Position = pos;
-                VDetailLog("{0},MoveLinear,terrainHeight,pos={1}", m_prim.LocalID, pos);
+                VDetailLog("{0},MoveLinear,terrainHeight,terrainHeight={1},pos={2}", m_prim.LocalID, terrainHeight, pos);
             }
 
             // Check if hovering
@@ -606,11 +573,11 @@ namespace OpenSim.Region.Physics.BulletSPlugin
                 // We should hover, get the target height
                 if ((m_flags & VehicleFlag.HOVER_WATER_ONLY) != 0)
                 {
-                    m_VhoverTargetHeight = m_prim.Scene.GetWaterLevel() + m_VhoverHeight;
+                    m_VhoverTargetHeight = m_prim.Scene.GetWaterLevelAtXYZ(pos) + m_VhoverHeight;
                 }
                 if ((m_flags & VehicleFlag.HOVER_TERRAIN_ONLY) != 0)
                 {
-                    m_VhoverTargetHeight = m_prim.Scene.TerrainManager.GetTerrainHeightAtXY(pos.X, pos.Y) + m_VhoverHeight;
+                    m_VhoverTargetHeight = terrainHeight + m_VhoverHeight;
                 }
                 if ((m_flags & VehicleFlag.HOVER_GLOBAL_HEIGHT) != 0)
                 {
@@ -635,82 +602,92 @@ namespace OpenSim.Region.Physics.BulletSPlugin
                     // Replace Vertical speed with correction figure if significant
                     if (Math.Abs(herr0) > 0.01f)
                     {
-                        m_dir.Z = -((herr0 * pTimestep * 50.0f) / m_VhoverTimescale);
+                        m_newVelocity.Z = -((herr0 * pTimestep * 50.0f) / m_VhoverTimescale);
                         //KF: m_VhoverEfficiency is not yet implemented
                     }
                     else
                     {
-                        m_dir.Z = 0f;
+                        m_newVelocity.Z = 0f;
                     }
                 }
 
-                VDetailLog("{0},MoveLinear,hover,pos={1},dir={2},height={3},target={4}", m_prim.LocalID, pos, m_dir, m_VhoverHeight, m_VhoverTargetHeight);
+                VDetailLog("{0},MoveLinear,hover,pos={1},dir={2},height={3},target={4}", m_prim.LocalID, pos, m_newVelocity, m_VhoverHeight, m_VhoverTargetHeight);
+            }
 
-//                m_VhoverEfficiency = 0f;    // 0=boucy, 1=Crit.damped
-//                m_VhoverTimescale = 0f;        // time to acheive height
-//                pTimestep  is time since last frame,in secs
+            Vector3 posChange = pos - m_lastPositionVector;
+            if (m_BlockingEndPoint != Vector3.Zero)
+            {
+                bool changed = false;
+                if (pos.X >= (m_BlockingEndPoint.X - (float)1))
+                {
+                    pos.X -= posChange.X + 1;
+                    changed = true;
+                }
+                if (pos.Y >= (m_BlockingEndPoint.Y - (float)1))
+                {
+                    pos.Y -= posChange.Y + 1;
+                    changed = true;
+                }
+                if (pos.Z >= (m_BlockingEndPoint.Z - (float)1))
+                {
+                    pos.Z -= posChange.Z + 1;
+                    changed = true;
+                }
+                if (pos.X <= 0)
+                {
+                    pos.X += posChange.X + 1;
+                    changed = true;
+                }
+                if (pos.Y <= 0)
+                {
+                    pos.Y += posChange.Y + 1;
+                    changed = true;
+                }
+                if (changed)
+                {
+                    m_prim.Position = pos;
+                    VDetailLog("{0},MoveLinear,blockingEndPoint,block={1},origPos={2},pos={3}",
+                                m_prim.LocalID, m_BlockingEndPoint, posChange, pos);
+                }
             }
 
+            float Zchange = Math.Abs(posChange.Z);
             if ((m_flags & (VehicleFlag.LIMIT_MOTOR_UP)) != 0)
             {
-                //Start Experimental Values
                 if (Zchange > .3)
-                {
                     grav.Z = (float)(grav.Z * 3);
-                }
                 if (Zchange > .15)
-                {
                     grav.Z = (float)(grav.Z * 2);
-                }
                 if (Zchange > .75)
-                {
                     grav.Z = (float)(grav.Z * 1.5);
-                }
                 if (Zchange > .05)
-                {
                     grav.Z = (float)(grav.Z * 1.25);
-                }
                 if (Zchange > .025)
-                {
                     grav.Z = (float)(grav.Z * 1.125);
-                }
-                float terraintemp = m_prim.Scene.TerrainManager.GetTerrainHeightAtXYZ(pos);
-                float postemp = (pos.Z - terraintemp);
+                float postemp = (pos.Z - terrainHeight);
                 if (postemp > 2.5f)
-                {
                     grav.Z = (float)(grav.Z * 1.037125);
-                }
                 VDetailLog("{0},MoveLinear,limitMotorUp,grav={1}", m_prim.LocalID, grav);
-                //End Experimental Values
             }
             if ((m_flags & (VehicleFlag.NO_X)) != 0)
-            {
-                m_dir.X = 0;
-            }
+                m_newVelocity.X = 0;
             if ((m_flags & (VehicleFlag.NO_Y)) != 0)
-            {
-                m_dir.Y = 0;
-            }
+                m_newVelocity.Y = 0;
             if ((m_flags & (VehicleFlag.NO_Z)) != 0)
-            {
-                m_dir.Z = 0;
-            }
-
-            m_lastPositionVector = m_prim.Position;
+                m_newVelocity.Z = 0;
 
             // Apply velocity
-            m_prim.Velocity = m_dir;
+            m_prim.Velocity = m_newVelocity;
             // apply gravity force
             // Why is this set here? The physics engine already does gravity.
             // m_prim.AddForce(grav, false);
-            // m_prim.Force = grav;
 
             // Apply friction
-            Vector3 decayamount = Vector3.One / (m_linearFrictionTimescale / pTimestep);
-            m_lastLinearVelocityVector -= m_lastLinearVelocityVector * decayamount;
+            Vector3 keepFraction = Vector3.One - (Vector3.One / (m_linearFrictionTimescale / pTimestep));
+            m_lastLinearVelocityVector *= keepFraction;
 
-            VDetailLog("{0},MoveLinear,done,pos={1},vel={2},force={3},decay={4}", 
-                        m_prim.LocalID, m_lastPositionVector, m_dir, grav, decayamount);
+            VDetailLog("{0},MoveLinear,done,lmDir={1},lmVel={2},newVel={3},grav={4},1Mdecay={5}", 
+                    m_prim.LocalID, m_linearMotorDirection, m_lastLinearVelocityVector, m_newVelocity, grav, keepFraction);
 
         } // end MoveLinear()
 
@@ -735,17 +712,18 @@ namespace OpenSim.Region.Physics.BulletSPlugin
                 // There are m_angularMotorApply steps.
                 Vector3 origAngularVelocity = m_angularMotorVelocity;
                 // ramp up to new value
-                //   current velocity  +=                         error                            /    (time to get there / step interval)
-                //                               requested speed            -  last motor speed
+                //   current velocity    +=                         error                          /    (  time to get there   / step interval)
+                //                               requested speed       -       last motor speed
                 m_angularMotorVelocity.X += (m_angularMotorDirection.X - m_angularMotorVelocity.X) /  (m_angularMotorTimescale / pTimestep);
                 m_angularMotorVelocity.Y += (m_angularMotorDirection.Y - m_angularMotorVelocity.Y) /  (m_angularMotorTimescale / pTimestep);
                 m_angularMotorVelocity.Z += (m_angularMotorDirection.Z - m_angularMotorVelocity.Z) /  (m_angularMotorTimescale / pTimestep);
 
-                VDetailLog("{0},MoveAngular,angularMotorApply,apply={1},origvel={2},dir={3},vel={4}", 
-                        m_prim.LocalID,m_angularMotorApply,origAngularVelocity, m_angularMotorDirection, m_angularMotorVelocity);
+                VDetailLog("{0},MoveAngular,angularMotorApply,apply={1},angTScale={2},timeStep={3},origvel={4},dir={5},vel={6}", 
+                        m_prim.LocalID, m_angularMotorApply, m_angularMotorTimescale, pTimestep, origAngularVelocity, m_angularMotorDirection, m_angularMotorVelocity);
 
-                m_angularMotorApply--;        // This is done so that if script request rate is less than phys frame rate the expected
-                                            // velocity may still be acheived.
+                // This is done so that if script request rate is less than phys frame rate the expected
+                //    velocity may still be acheived.
+                m_angularMotorApply--;
             }
             else
             {
@@ -760,7 +738,7 @@ namespace OpenSim.Region.Physics.BulletSPlugin
             Vector3 vertattr = Vector3.Zero;
             if (m_verticalAttractionTimescale < 300)
             {
-                float VAservo = 0.2f / (m_verticalAttractionTimescale * pTimestep);
+                float VAservo = 0.2f / (m_verticalAttractionTimescale / pTimestep);
                 // get present body rotation
                 Quaternion rotq = m_prim.Orientation;
                 // make a vector pointing up
@@ -863,16 +841,12 @@ namespace OpenSim.Region.Physics.BulletSPlugin
                 m_rot.Y = 0;
                 changed = true;
             }
-            if ((m_flags & VehicleFlag.LOCK_ROTATION) != 0)
-            {
-                m_rot.X = 0;
-                m_rot.Y = 0;
-                changed = true;
-            }
             if (changed)
+            {
                 m_prim.Orientation = m_rot;
+                VDetailLog("{0},LimitRotation,done,orig={1},new={2}", m_prim.LocalID, rotq, m_rot);
+            }
 
-            VDetailLog("{0},LimitRotation,done,changed={1},orig={2},new={3}", m_prim.LocalID, changed, rotq, m_rot);
         }
 
         // Invoke the detailed logger and output something if it's enabled.