bullet: Sync with current upstream master branch

This updates our local copy to commit 5ec8339b6fc491e3f09a34a4516e82787f053fcc.
We need a recent master commit for some new features that we use in Godot
(see #25543 and #28909).

To avoid warnings generated by Bullet headers included in our own module,
we include those headers with -isystem on GCC and Clang.

Fixes #29503.

8 files changed, 860 insertions, 208 deletions

diff --git a/thirdparty/bullet/BulletDynamics/ConstraintSolver/btBatchedConstraints.cpp b/thirdparty/bullet/BulletDynamics/ConstraintSolver/btBatchedConstraints.cpp
index b51dfaad3c..2a5efc6495 100644
--- a/thirdparty/bullet/BulletDynamics/ConstraintSolver/btBatchedConstraints.cpp
+++ b/thirdparty/bullet/BulletDynamics/ConstraintSolver/btBatchedConstraints.cpp
@@ -22,6 +22,8 @@ subject to the following restrictions:
 
 #include <string.h>  //for memset
 
+#include <cmath>
+
 const int kNoMerge = -1;
 
 bool btBatchedConstraints::s_debugDrawBatches = false;
@@ -520,7 +522,7 @@ static void writeGrainSizes(btBatchedConstraints* bc)
 	{
 		const Range& phase = bc->m_phases[iPhase];
 		int numBatches = phase.end - phase.begin;
-		float grainSize = floor((0.25f * numBatches / float(numThreads)) + 0.0f);
+		float grainSize = std::floor((0.25f * numBatches / float(numThreads)) + 0.0f);
 		bc->m_phaseGrainSize[iPhase] = btMax(1, int(grainSize));
 	}
 }
diff --git a/thirdparty/bullet/BulletDynamics/ConstraintSolver/btConeTwistConstraint.cpp b/thirdparty/bullet/BulletDynamics/ConstraintSolver/btConeTwistConstraint.cpp
index 10678b2a61..ac046aa6ea 100644
--- a/thirdparty/bullet/BulletDynamics/ConstraintSolver/btConeTwistConstraint.cpp
+++ b/thirdparty/bullet/BulletDynamics/ConstraintSolver/btConeTwistConstraint.cpp
@@ -19,6 +19,7 @@ Written by: Marcus Hennix
 #include "BulletDynamics/Dynamics/btRigidBody.h"
 #include "LinearMath/btTransformUtil.h"
 #include "LinearMath/btMinMax.h"
+#include <cmath>
 #include <new>
 
 //#define CONETWIST_USE_OBSOLETE_SOLVER true
@@ -842,7 +843,7 @@ void btConeTwistConstraint::computeConeLimitInfo(const btQuaternion& qCone,
 			btScalar norm = 1 / (m_swingSpan2 * m_swingSpan2);
 			norm += surfaceSlope2 / (m_swingSpan1 * m_swingSpan1);
 			btScalar swingLimit2 = (1 + surfaceSlope2) / norm;
-			swingLimit = sqrt(swingLimit2);
+			swingLimit = std::sqrt(swingLimit2);
 		}
 
 		// test!
@@ -887,7 +888,7 @@ btVector3 btConeTwistConstraint::GetPointForAngle(btScalar fAngleInRadians, btSc
 		btScalar norm = 1 / (m_swingSpan2 * m_swingSpan2);
 		norm += surfaceSlope2 / (m_swingSpan1 * m_swingSpan1);
 		btScalar swingLimit2 = (1 + surfaceSlope2) / norm;
-		swingLimit = sqrt(swingLimit2);
+		swingLimit = std::sqrt(swingLimit2);
 	}
 
 	// convert into point in constraint space:
diff --git a/thirdparty/bullet/BulletDynamics/ConstraintSolver/btConstraintSolver.h b/thirdparty/bullet/BulletDynamics/ConstraintSolver/btConstraintSolver.h
index 808433477c..68a4a07a1d 100644
--- a/thirdparty/bullet/BulletDynamics/ConstraintSolver/btConstraintSolver.h
+++ b/thirdparty/bullet/BulletDynamics/ConstraintSolver/btConstraintSolver.h
@@ -35,6 +35,7 @@ enum btConstraintSolverType
 	BT_MLCP_SOLVER = 2,
 	BT_NNCG_SOLVER = 4,
 	BT_MULTIBODY_SOLVER = 8,
+	BT_BLOCK_SOLVER = 16,
 };
 
 class btConstraintSolver
diff --git a/thirdparty/bullet/BulletDynamics/ConstraintSolver/btContactSolverInfo.h b/thirdparty/bullet/BulletDynamics/ConstraintSolver/btContactSolverInfo.h
index 89f8db8b1a..63d7c98e16 100644
--- a/thirdparty/bullet/BulletDynamics/ConstraintSolver/btContactSolverInfo.h
+++ b/thirdparty/bullet/BulletDynamics/ConstraintSolver/btContactSolverInfo.h
@@ -64,6 +64,7 @@ struct btContactSolverInfoData
 	btScalar m_restitutionVelocityThreshold;
 	bool m_jointFeedbackInWorldSpace;
 	bool m_jointFeedbackInJointFrame;
+	int m_reportSolverAnalytics;
 };
 
 struct btContactSolverInfo : public btContactSolverInfoData
@@ -98,6 +99,7 @@ struct btContactSolverInfo : public btContactSolverInfoData
 		m_restitutionVelocityThreshold = 0.2f;  //if the relative velocity is below this threshold, there is zero restitution
 		m_jointFeedbackInWorldSpace = false;
 		m_jointFeedbackInJointFrame = false;
+		m_reportSolverAnalytics = 0;
 	}
 };
 
diff --git a/thirdparty/bullet/BulletDynamics/ConstraintSolver/btGeneric6DofSpring2Constraint.cpp b/thirdparty/bullet/BulletDynamics/ConstraintSolver/btGeneric6DofSpring2Constraint.cpp
index 49c8d9bbf7..9a3b39e6f8 100644
--- a/thirdparty/bullet/BulletDynamics/ConstraintSolver/btGeneric6DofSpring2Constraint.cpp
+++ b/thirdparty/bullet/BulletDynamics/ConstraintSolver/btGeneric6DofSpring2Constraint.cpp
@@ -32,7 +32,7 @@ Cons:
 
 /*
 2007-09-09
-btGeneric6DofConstraint Refactored by Francisco Le?n
+btGeneric6DofConstraint Refactored by Francisco Leon
 email: projectileman@yahoo.com
 http://gimpact.sf.net
 */
@@ -40,6 +40,7 @@ http://gimpact.sf.net
 #include "btGeneric6DofSpring2Constraint.h"
 #include "BulletDynamics/Dynamics/btRigidBody.h"
 #include "LinearMath/btTransformUtil.h"
+#include <cmath>
 #include <new>
 
 btGeneric6DofSpring2Constraint::btGeneric6DofSpring2Constraint(btRigidBody& rbA, btRigidBody& rbB, const btTransform& frameInA, const btTransform& frameInB, RotateOrder rotOrder)
@@ -310,9 +311,9 @@ void btGeneric6DofSpring2Constraint::calculateAngleInfo()
 		case RO_XYZ:
 		{
 			//Is this the "line of nodes" calculation choosing planes YZ (B coordinate system) and xy (A coordinate system)? (http://en.wikipedia.org/wiki/Euler_angles)
-			//The two planes are non-homologous, so this is a Tait–Bryan angle formalism and not a proper Euler
+			//The two planes are non-homologous, so this is a Tait-Bryan angle formalism and not a proper Euler
 			//Extrinsic rotations are equal to the reversed order intrinsic rotations so the above xyz extrinsic rotations (axes are fixed) are the same as the zy'x" intrinsic rotations (axes are refreshed after each rotation)
-			//that is why xy and YZ planes are chosen (this will describe a zy'x" intrinsic rotation) (see the figure on the left at http://en.wikipedia.org/wiki/Euler_angles under Tait–Bryan angles)
+			//that is why xy and YZ planes are chosen (this will describe a zy'x" intrinsic rotation) (see the figure on the left at http://en.wikipedia.org/wiki/Euler_angles under Tait-Bryan angles)
 			// x' = Nperp = N.cross(axis2)
 			// y' = N = axis2.cross(axis0)
 			// z' = z
@@ -845,7 +846,7 @@ int btGeneric6DofSpring2Constraint::get_limit_motor_info2(
 		if (m_rbA.getInvMass() == 0) m = mB; else
 		if (m_rbB.getInvMass() == 0) m = mA; else
 			m = mA*mB / (mA + mB);
-		btScalar angularfreq = sqrt(ks / m);
+		btScalar angularfreq = btSqrt(ks / m);
 
 		//limit stiffness (the spring should not be sampled faster that the quarter of its angular frequency)
 		if (limot->m_springStiffnessLimited && 0.25 < angularfreq * dt)
@@ -865,7 +866,7 @@ int btGeneric6DofSpring2Constraint::get_limit_motor_info2(
 		// vel + f / m * (rotational ? -1 : 1)
 		// so in theory this should be set here for m_constraintError
 		// (with m_constraintError we set a desired velocity for the affected body(es))
-		// however in practice any value is fine as long as it is greater then the "proper" velocity,
+		// however in practice any value is fine as long as it is greater than the "proper" velocity,
 		// because the m_lowerLimit and the m_upperLimit will determinate the strength of the final pulling force
 		// so it is much simpler (and more robust) just to simply use inf (with the proper sign)
 		// (Even with our best intent the "new" velocity is only an estimation. If we underestimate
@@ -1085,7 +1086,7 @@ void btGeneric6DofSpring2Constraint::setServoTarget(int index, btScalar targetOr
 		btScalar target = targetOrg + SIMD_PI;
 		if (1)
 		{
-			btScalar m = target - SIMD_2_PI * floor(target / SIMD_2_PI);
+			btScalar m = target - SIMD_2_PI * std::floor(target / SIMD_2_PI);
 			// handle boundary cases resulted from floating-point cut off:
 			{
 				if (m >= SIMD_2_PI)
diff --git a/thirdparty/bullet/BulletDynamics/ConstraintSolver/btGeneric6DofSpring2Constraint.h b/thirdparty/bullet/BulletDynamics/ConstraintSolver/btGeneric6DofSpring2Constraint.h
index bc3ee6d210..00e24364e0 100644
--- a/thirdparty/bullet/BulletDynamics/ConstraintSolver/btGeneric6DofSpring2Constraint.h
+++ b/thirdparty/bullet/BulletDynamics/ConstraintSolver/btGeneric6DofSpring2Constraint.h
@@ -294,7 +294,7 @@ protected:
 	bool m_hasStaticBody;
 	int m_flags;
 
-	btGeneric6DofSpring2Constraint& operator=(btGeneric6DofSpring2Constraint&)
+	btGeneric6DofSpring2Constraint& operator=(const btGeneric6DofSpring2Constraint&)
 	{
 		btAssert(0);
 		return *this;
diff --git a/thirdparty/bullet/BulletDynamics/ConstraintSolver/btSequentialImpulseConstraintSolver.cpp b/thirdparty/bullet/BulletDynamics/ConstraintSolver/btSequentialImpulseConstraintSolver.cpp
index def3227b43..d3b71e4583 100644
--- a/thirdparty/bullet/BulletDynamics/ConstraintSolver/btSequentialImpulseConstraintSolver.cpp
+++ b/thirdparty/bullet/BulletDynamics/ConstraintSolver/btSequentialImpulseConstraintSolver.cpp
@@ -394,6 +394,18 @@ btSingleConstraintRowSolver btSequentialImpulseConstraintSolver::getScalarConstr
 	return gResolveSingleConstraintRowLowerLimit_scalar_reference;
 }
 
+btSingleConstraintRowSolver btSequentialImpulseConstraintSolver::getScalarSplitPenetrationImpulseGeneric()
+{
+	return gResolveSplitPenetrationImpulse_scalar_reference;
+}
+
+btSingleConstraintRowSolver btSequentialImpulseConstraintSolver::getSSE2SplitPenetrationImpulseGeneric()
+{
+	return gResolveSplitPenetrationImpulse_sse2;
+}
+
+
+
 #ifdef USE_SIMD
 btSingleConstraintRowSolver btSequentialImpulseConstraintSolver::getSSE2ConstraintRowSolverGeneric()
 {
@@ -421,6 +433,11 @@ unsigned long btSequentialImpulseConstraintSolver::btRand2()
 	return m_btSeed2;
 }
 
+unsigned long btSequentialImpulseConstraintSolver::btRand2a(unsigned long& seed)
+{
+	seed = (1664525L * seed + 1013904223L) & 0xffffffff;
+	return seed;
+}
 //See ODE: adam's all-int straightforward(?) dRandInt (0..n-1)
 int btSequentialImpulseConstraintSolver::btRandInt2(int n)
 {
@@ -454,42 +471,44 @@ int btSequentialImpulseConstraintSolver::btRandInt2(int n)
 	return (int)(r % un);
 }
 
-void btSequentialImpulseConstraintSolver::initSolverBody(btSolverBody* solverBody, btCollisionObject* collisionObject, btScalar timeStep)
+int btSequentialImpulseConstraintSolver::btRandInt2a(int n, unsigned long& seed)
 {
-	btRigidBody* rb = collisionObject ? btRigidBody::upcast(collisionObject) : 0;
-
-	solverBody->internalGetDeltaLinearVelocity().setValue(0.f, 0.f, 0.f);
-	solverBody->internalGetDeltaAngularVelocity().setValue(0.f, 0.f, 0.f);
-	solverBody->internalGetPushVelocity().setValue(0.f, 0.f, 0.f);
-	solverBody->internalGetTurnVelocity().setValue(0.f, 0.f, 0.f);
+	// seems good; xor-fold and modulus
+	const unsigned long un = static_cast<unsigned long>(n);
+	unsigned long r = btSequentialImpulseConstraintSolver::btRand2a(seed);
 
-	if (rb)
-	{
-		solverBody->m_worldTransform = rb->getWorldTransform();
-		solverBody->internalSetInvMass(btVector3(rb->getInvMass(), rb->getInvMass(), rb->getInvMass()) * rb->getLinearFactor());
-		solverBody->m_originalBody = rb;
-		solverBody->m_angularFactor = rb->getAngularFactor();
-		solverBody->m_linearFactor = rb->getLinearFactor();
-		solverBody->m_linearVelocity = rb->getLinearVelocity();
-		solverBody->m_angularVelocity = rb->getAngularVelocity();
-		solverBody->m_externalForceImpulse = rb->getTotalForce() * rb->getInvMass() * timeStep;
-		solverBody->m_externalTorqueImpulse = rb->getTotalTorque() * rb->getInvInertiaTensorWorld() * timeStep;
-	}
-	else
+	// note: probably more aggressive than it needs to be -- might be
+	//       able to get away without one or two of the innermost branches.
+	if (un <= 0x00010000UL)
 	{
-		solverBody->m_worldTransform.setIdentity();
-		solverBody->internalSetInvMass(btVector3(0, 0, 0));
-		solverBody->m_originalBody = 0;
-		solverBody->m_angularFactor.setValue(1, 1, 1);
-		solverBody->m_linearFactor.setValue(1, 1, 1);
-		solverBody->m_linearVelocity.setValue(0, 0, 0);
-		solverBody->m_angularVelocity.setValue(0, 0, 0);
-		solverBody->m_externalForceImpulse.setValue(0, 0, 0);
-		solverBody->m_externalTorqueImpulse.setValue(0, 0, 0);
+		r ^= (r >> 16);
+		if (un <= 0x00000100UL)
+		{
+			r ^= (r >> 8);
+			if (un <= 0x00000010UL)
+			{
+				r ^= (r >> 4);
+				if (un <= 0x00000004UL)
+				{
+					r ^= (r >> 2);
+					if (un <= 0x00000002UL)
+					{
+						r ^= (r >> 1);
+					}
+				}
+			}
+		}
 	}
+
+	return (int)(r % un);
 }
 
-btScalar btSequentialImpulseConstraintSolver::restitutionCurve(btScalar rel_vel, btScalar restitution, btScalar velocityThreshold)
+void btSequentialImpulseConstraintSolver::initSolverBody(btSolverBody* solverBody, btCollisionObject* collisionObject, btScalar timeStep)
+{
+	btSISolverSingleIterationData::initSolverBody(solverBody, collisionObject, timeStep);
+}
+
+btScalar btSequentialImpulseConstraintSolver::restitutionCurveInternal(btScalar rel_vel, btScalar restitution, btScalar velocityThreshold)
 {
 	//printf("rel_vel =%f\n", rel_vel);
 	if (btFabs(rel_vel) < velocityThreshold)
@@ -498,6 +517,10 @@ btScalar btSequentialImpulseConstraintSolver::restitutionCurve(btScalar rel_vel,
 	btScalar rest = restitution * -rel_vel;
 	return rest;
 }
+btScalar btSequentialImpulseConstraintSolver::restitutionCurve(btScalar rel_vel, btScalar restitution, btScalar velocityThreshold)
+{
+	return btSequentialImpulseConstraintSolver::restitutionCurveInternal(rel_vel, restitution, velocityThreshold);
+}
 
 void btSequentialImpulseConstraintSolver::applyAnisotropicFriction(btCollisionObject* colObj, btVector3& frictionDirection, int frictionMode)
 {
@@ -513,13 +536,13 @@ void btSequentialImpulseConstraintSolver::applyAnisotropicFriction(btCollisionOb
 	}
 }
 
-void btSequentialImpulseConstraintSolver::setupFrictionConstraint(btSolverConstraint& solverConstraint, const btVector3& normalAxis, int solverBodyIdA, int solverBodyIdB, btManifoldPoint& cp, const btVector3& rel_pos1, const btVector3& rel_pos2, btCollisionObject* colObj0, btCollisionObject* colObj1, btScalar relaxation, const btContactSolverInfo& infoGlobal, btScalar desiredVelocity, btScalar cfmSlip)
+void btSequentialImpulseConstraintSolver::setupFrictionConstraintInternal(btAlignedObjectArray<btSolverBody>& tmpSolverBodyPool, btSolverConstraint& solverConstraint, const btVector3& normalAxis, int solverBodyIdA, int solverBodyIdB, btManifoldPoint& cp, const btVector3& rel_pos1, const btVector3& rel_pos2, btCollisionObject* colObj0, btCollisionObject* colObj1, btScalar relaxation, const btContactSolverInfo& infoGlobal, btScalar desiredVelocity, btScalar cfmSlip)
 {
-	btSolverBody& solverBodyA = m_tmpSolverBodyPool[solverBodyIdA];
-	btSolverBody& solverBodyB = m_tmpSolverBodyPool[solverBodyIdB];
+	btSolverBody& solverBodyA = tmpSolverBodyPool[solverBodyIdA];
+	btSolverBody& solverBodyB = tmpSolverBodyPool[solverBodyIdB];
 
-	btRigidBody* body0 = m_tmpSolverBodyPool[solverBodyIdA].m_originalBody;
-	btRigidBody* bodyA = m_tmpSolverBodyPool[solverBodyIdB].m_originalBody;
+	btRigidBody* body0 = tmpSolverBodyPool[solverBodyIdA].m_originalBody;
+	btRigidBody* bodyA = tmpSolverBodyPool[solverBodyIdB].m_originalBody;
 
 	solverConstraint.m_solverBodyIdA = solverBodyIdA;
 	solverConstraint.m_solverBodyIdB = solverBodyIdB;
@@ -605,30 +628,47 @@ void btSequentialImpulseConstraintSolver::setupFrictionConstraint(btSolverConstr
 	}
 }
 
+void btSequentialImpulseConstraintSolver::setupFrictionConstraint(btSolverConstraint& solverConstraint, const btVector3& normalAxis, int solverBodyIdA, int solverBodyIdB, btManifoldPoint& cp, const btVector3& rel_pos1, const btVector3& rel_pos2, btCollisionObject* colObj0, btCollisionObject* colObj1, btScalar relaxation, const btContactSolverInfo& infoGlobal, btScalar desiredVelocity, btScalar cfmSlip)
+{
+	btSequentialImpulseConstraintSolver::setupFrictionConstraintInternal(m_tmpSolverBodyPool, solverConstraint, normalAxis, solverBodyIdA, solverBodyIdB, cp, rel_pos1, rel_pos2, colObj0, colObj1, relaxation, infoGlobal, desiredVelocity, cfmSlip);
+}
+
+btSolverConstraint& btSequentialImpulseConstraintSolver::addFrictionConstraintInternal(btAlignedObjectArray<btSolverBody>& tmpSolverBodyPool, btConstraintArray& tmpSolverContactFrictionConstraintPool, const btVector3& normalAxis, int solverBodyIdA, int solverBodyIdB, int frictionIndex, btManifoldPoint& cp, const btVector3& rel_pos1, const btVector3& rel_pos2, btCollisionObject* colObj0, btCollisionObject* colObj1, btScalar relaxation, const btContactSolverInfo& infoGlobal, btScalar desiredVelocity, btScalar cfmSlip)
+{
+	btSolverConstraint& solverConstraint = tmpSolverContactFrictionConstraintPool.expandNonInitializing();
+	solverConstraint.m_frictionIndex = frictionIndex;
+	setupFrictionConstraintInternal(tmpSolverBodyPool, solverConstraint, normalAxis, solverBodyIdA, solverBodyIdB, cp, rel_pos1, rel_pos2,
+		colObj0, colObj1, relaxation, infoGlobal, desiredVelocity, cfmSlip);
+	return solverConstraint;
+}
+
+
+
 btSolverConstraint& btSequentialImpulseConstraintSolver::addFrictionConstraint(const btVector3& normalAxis, int solverBodyIdA, int solverBodyIdB, int frictionIndex, btManifoldPoint& cp, const btVector3& rel_pos1, const btVector3& rel_pos2, btCollisionObject* colObj0, btCollisionObject* colObj1, btScalar relaxation, const btContactSolverInfo& infoGlobal, btScalar desiredVelocity, btScalar cfmSlip)
 {
 	btSolverConstraint& solverConstraint = m_tmpSolverContactFrictionConstraintPool.expandNonInitializing();
 	solverConstraint.m_frictionIndex = frictionIndex;
 	setupFrictionConstraint(solverConstraint, normalAxis, solverBodyIdA, solverBodyIdB, cp, rel_pos1, rel_pos2,
-							colObj0, colObj1, relaxation, infoGlobal, desiredVelocity, cfmSlip);
+		colObj0, colObj1, relaxation, infoGlobal, desiredVelocity, cfmSlip);
 	return solverConstraint;
 }
 
-void btSequentialImpulseConstraintSolver::setupTorsionalFrictionConstraint(btSolverConstraint& solverConstraint, const btVector3& normalAxis1, int solverBodyIdA, int solverBodyIdB,
-																		   btManifoldPoint& cp, btScalar combinedTorsionalFriction, const btVector3& rel_pos1, const btVector3& rel_pos2,
-																		   btCollisionObject* colObj0, btCollisionObject* colObj1, btScalar relaxation,
-																		   btScalar desiredVelocity, btScalar cfmSlip)
+
+void btSequentialImpulseConstraintSolver::setupTorsionalFrictionConstraintInternal(btAlignedObjectArray<btSolverBody>& tmpSolverBodyPool, btSolverConstraint& solverConstraint, const btVector3& normalAxis1, int solverBodyIdA, int solverBodyIdB,
+	btManifoldPoint& cp, btScalar combinedTorsionalFriction, const btVector3& rel_pos1, const btVector3& rel_pos2,
+	btCollisionObject* colObj0, btCollisionObject* colObj1, btScalar relaxation,
+	btScalar desiredVelocity, btScalar cfmSlip)
 
 {
 	btVector3 normalAxis(0, 0, 0);
 
 	solverConstraint.m_contactNormal1 = normalAxis;
 	solverConstraint.m_contactNormal2 = -normalAxis;
-	btSolverBody& solverBodyA = m_tmpSolverBodyPool[solverBodyIdA];
-	btSolverBody& solverBodyB = m_tmpSolverBodyPool[solverBodyIdB];
+	btSolverBody& solverBodyA = tmpSolverBodyPool[solverBodyIdA];
+	btSolverBody& solverBodyB = tmpSolverBodyPool[solverBodyIdB];
 
-	btRigidBody* body0 = m_tmpSolverBodyPool[solverBodyIdA].m_originalBody;
-	btRigidBody* bodyA = m_tmpSolverBodyPool[solverBodyIdB].m_originalBody;
+	btRigidBody* body0 = tmpSolverBodyPool[solverBodyIdA].m_originalBody;
+	btRigidBody* bodyA = tmpSolverBodyPool[solverBodyIdB].m_originalBody;
 
 	solverConstraint.m_solverBodyIdA = solverBodyIdA;
 	solverConstraint.m_solverBodyIdB = solverBodyIdB;
@@ -677,15 +717,250 @@ void btSequentialImpulseConstraintSolver::setupTorsionalFrictionConstraint(btSol
 	}
 }
 
+
+void btSequentialImpulseConstraintSolver::setupTorsionalFrictionConstraint(btSolverConstraint& solverConstraint, const btVector3& normalAxis1, int solverBodyIdA, int solverBodyIdB,
+	btManifoldPoint& cp, btScalar combinedTorsionalFriction, const btVector3& rel_pos1, const btVector3& rel_pos2,
+	btCollisionObject* colObj0, btCollisionObject* colObj1, btScalar relaxation,
+	btScalar desiredVelocity, btScalar cfmSlip)
+
+{
+	setupTorsionalFrictionConstraintInternal(m_tmpSolverBodyPool, solverConstraint, normalAxis1, solverBodyIdA, solverBodyIdB,
+		cp, combinedTorsionalFriction, rel_pos1, rel_pos2,
+		colObj0, colObj1, relaxation,
+		desiredVelocity, cfmSlip);
+
+}
+
+btSolverConstraint& btSequentialImpulseConstraintSolver::addTorsionalFrictionConstraintInternal(btAlignedObjectArray<btSolverBody>& tmpSolverBodyPool, btConstraintArray& tmpSolverContactRollingFrictionConstraintPool, const btVector3& normalAxis, int solverBodyIdA, int solverBodyIdB, int frictionIndex, btManifoldPoint& cp, btScalar combinedTorsionalFriction, const btVector3& rel_pos1, const btVector3& rel_pos2, btCollisionObject* colObj0, btCollisionObject* colObj1, btScalar relaxation, btScalar desiredVelocity, btScalar cfmSlip)
+{
+	btSolverConstraint& solverConstraint = tmpSolverContactRollingFrictionConstraintPool.expandNonInitializing();
+	solverConstraint.m_frictionIndex = frictionIndex;
+	setupTorsionalFrictionConstraintInternal(tmpSolverBodyPool, solverConstraint, normalAxis, solverBodyIdA, solverBodyIdB, cp, combinedTorsionalFriction, rel_pos1, rel_pos2,
+		colObj0, colObj1, relaxation, desiredVelocity, cfmSlip);
+	return solverConstraint;
+}
+
+
 btSolverConstraint& btSequentialImpulseConstraintSolver::addTorsionalFrictionConstraint(const btVector3& normalAxis, int solverBodyIdA, int solverBodyIdB, int frictionIndex, btManifoldPoint& cp, btScalar combinedTorsionalFriction, const btVector3& rel_pos1, const btVector3& rel_pos2, btCollisionObject* colObj0, btCollisionObject* colObj1, btScalar relaxation, btScalar desiredVelocity, btScalar cfmSlip)
 {
 	btSolverConstraint& solverConstraint = m_tmpSolverContactRollingFrictionConstraintPool.expandNonInitializing();
 	solverConstraint.m_frictionIndex = frictionIndex;
 	setupTorsionalFrictionConstraint(solverConstraint, normalAxis, solverBodyIdA, solverBodyIdB, cp, combinedTorsionalFriction, rel_pos1, rel_pos2,
-									 colObj0, colObj1, relaxation, desiredVelocity, cfmSlip);
+		colObj0, colObj1, relaxation, desiredVelocity, cfmSlip);
 	return solverConstraint;
 }
 
+int btSISolverSingleIterationData::getOrInitSolverBody(btCollisionObject & body, btScalar timeStep)
+{
+#if BT_THREADSAFE
+	int solverBodyId = -1;
+	bool isRigidBodyType = btRigidBody::upcast(&body) != NULL;
+	if (isRigidBodyType && !body.isStaticOrKinematicObject())
+	{
+		// dynamic body
+		// Dynamic bodies can only be in one island, so it's safe to write to the companionId
+		solverBodyId = body.getCompanionId();
+		if (solverBodyId < 0)
+		{
+			solverBodyId = m_tmpSolverBodyPool.size();
+			btSolverBody& solverBody = m_tmpSolverBodyPool.expand();
+			initSolverBody(&solverBody, &body, timeStep);
+			body.setCompanionId(solverBodyId);
+		}
+	}
+	else if (isRigidBodyType && body.isKinematicObject())
+	{
+		//
+		// NOTE: must test for kinematic before static because some kinematic objects also
+		//   identify as "static"
+		//
+		// Kinematic bodies can be in multiple islands at once, so it is a
+		// race condition to write to them, so we use an alternate method
+		// to record the solverBodyId
+		int uniqueId = body.getWorldArrayIndex();
+		const int INVALID_SOLVER_BODY_ID = -1;
+		if (uniqueId >= m_kinematicBodyUniqueIdToSolverBodyTable.size())
+		{
+			m_kinematicBodyUniqueIdToSolverBodyTable.resize(uniqueId + 1, INVALID_SOLVER_BODY_ID);
+		}
+		solverBodyId = m_kinematicBodyUniqueIdToSolverBodyTable[uniqueId];
+		// if no table entry yet,
+		if (solverBodyId == INVALID_SOLVER_BODY_ID)
+		{
+			// create a table entry for this body
+			solverBodyId = m_tmpSolverBodyPool.size();
+			btSolverBody& solverBody = m_tmpSolverBodyPool.expand();
+			initSolverBody(&solverBody, &body, timeStep);
+			m_kinematicBodyUniqueIdToSolverBodyTable[uniqueId] = solverBodyId;
+		}
+	}
+	else
+	{
+		bool isMultiBodyType = (body.getInternalType() & btCollisionObject::CO_FEATHERSTONE_LINK);
+		// Incorrectly set collision object flags can degrade performance in various ways.
+		if (!isMultiBodyType)
+		{
+			btAssert(body.isStaticOrKinematicObject());
+		}
+		//it could be a multibody link collider
+		// all fixed bodies (inf mass) get mapped to a single solver id
+		if (m_fixedBodyId < 0)
+		{
+			m_fixedBodyId = m_tmpSolverBodyPool.size();
+			btSolverBody& fixedBody = m_tmpSolverBodyPool.expand();
+			initSolverBody(&fixedBody, 0, timeStep);
+		}
+		solverBodyId = m_fixedBodyId;
+	}
+	btAssert(solverBodyId >= 0 && solverBodyId < m_tmpSolverBodyPool.size());
+	return solverBodyId;
+#else   // BT_THREADSAFE
+
+	int solverBodyIdA = -1;
+
+	if (body.getCompanionId() >= 0)
+	{
+		//body has already been converted
+		solverBodyIdA = body.getCompanionId();
+		btAssert(solverBodyIdA < m_tmpSolverBodyPool.size());
+	}
+	else
+	{
+		btRigidBody* rb = btRigidBody::upcast(&body);
+		//convert both active and kinematic objects (for their velocity)
+		if (rb && (rb->getInvMass() || rb->isKinematicObject()))
+		{
+			solverBodyIdA = m_tmpSolverBodyPool.size();
+			btSolverBody& solverBody = m_tmpSolverBodyPool.expand();
+			initSolverBody(&solverBody, &body, timeStep);
+			body.setCompanionId(solverBodyIdA);
+		}
+		else
+		{
+			if (m_fixedBodyId < 0)
+			{
+				m_fixedBodyId = m_tmpSolverBodyPool.size();
+				btSolverBody& fixedBody = m_tmpSolverBodyPool.expand();
+				initSolverBody(&fixedBody, 0, timeStep);
+			}
+			return m_fixedBodyId;
+			//			return 0;//assume first one is a fixed solver body
+		}
+	}
+
+	return solverBodyIdA;
+#endif  // BT_THREADSAFE
+}
+void btSISolverSingleIterationData::initSolverBody(btSolverBody * solverBody, btCollisionObject * collisionObject, btScalar timeStep)
+{
+	btRigidBody* rb = collisionObject ? btRigidBody::upcast(collisionObject) : 0;
+
+	solverBody->internalGetDeltaLinearVelocity().setValue(0.f, 0.f, 0.f);
+	solverBody->internalGetDeltaAngularVelocity().setValue(0.f, 0.f, 0.f);
+	solverBody->internalGetPushVelocity().setValue(0.f, 0.f, 0.f);
+	solverBody->internalGetTurnVelocity().setValue(0.f, 0.f, 0.f);
+
+	if (rb)
+	{
+		solverBody->m_worldTransform = rb->getWorldTransform();
+		solverBody->internalSetInvMass(btVector3(rb->getInvMass(), rb->getInvMass(), rb->getInvMass()) * rb->getLinearFactor());
+		solverBody->m_originalBody = rb;
+		solverBody->m_angularFactor = rb->getAngularFactor();
+		solverBody->m_linearFactor = rb->getLinearFactor();
+		solverBody->m_linearVelocity = rb->getLinearVelocity();
+		solverBody->m_angularVelocity = rb->getAngularVelocity();
+		solverBody->m_externalForceImpulse = rb->getTotalForce() * rb->getInvMass() * timeStep;
+		solverBody->m_externalTorqueImpulse = rb->getTotalTorque() * rb->getInvInertiaTensorWorld() * timeStep;
+	}
+	else
+	{
+		solverBody->m_worldTransform.setIdentity();
+		solverBody->internalSetInvMass(btVector3(0, 0, 0));
+		solverBody->m_originalBody = 0;
+		solverBody->m_angularFactor.setValue(1, 1, 1);
+		solverBody->m_linearFactor.setValue(1, 1, 1);
+		solverBody->m_linearVelocity.setValue(0, 0, 0);
+		solverBody->m_angularVelocity.setValue(0, 0, 0);
+		solverBody->m_externalForceImpulse.setValue(0, 0, 0);
+		solverBody->m_externalTorqueImpulse.setValue(0, 0, 0);
+	}
+}
+
+int btSISolverSingleIterationData::getSolverBody(btCollisionObject& body) const
+{
+#if BT_THREADSAFE
+	int solverBodyId = -1;
+	bool isRigidBodyType = btRigidBody::upcast(&body) != NULL;
+	if (isRigidBodyType && !body.isStaticOrKinematicObject())
+	{
+		// dynamic body
+		// Dynamic bodies can only be in one island, so it's safe to write to the companionId
+		solverBodyId = body.getCompanionId();
+		btAssert(solverBodyId >= 0);
+	}
+	else if (isRigidBodyType && body.isKinematicObject())
+	{
+		//
+		// NOTE: must test for kinematic before static because some kinematic objects also
+		//   identify as "static"
+		//
+		// Kinematic bodies can be in multiple islands at once, so it is a
+		// race condition to write to them, so we use an alternate method
+		// to record the solverBodyId
+		int uniqueId = body.getWorldArrayIndex();
+		const int INVALID_SOLVER_BODY_ID = -1;
+		if (uniqueId >= m_kinematicBodyUniqueIdToSolverBodyTable.size())
+		{
+			m_kinematicBodyUniqueIdToSolverBodyTable.resize(uniqueId + 1, INVALID_SOLVER_BODY_ID);
+		}
+		solverBodyId = m_kinematicBodyUniqueIdToSolverBodyTable[uniqueId];
+		btAssert(solverBodyId != INVALID_SOLVER_BODY_ID);
+	}
+	else
+	{
+		bool isMultiBodyType = (body.getInternalType() & btCollisionObject::CO_FEATHERSTONE_LINK);
+		// Incorrectly set collision object flags can degrade performance in various ways.
+		if (!isMultiBodyType)
+		{
+			btAssert(body.isStaticOrKinematicObject());
+		}
+		btAssert(m_fixedBodyId >= 0);
+		solverBodyId = m_fixedBodyId;
+	}
+	btAssert(solverBodyId >= 0 && solverBodyId < m_tmpSolverBodyPool.size());
+	return solverBodyId;
+#else   // BT_THREADSAFE
+	int solverBodyIdA = -1;
+
+	if (body.getCompanionId() >= 0)
+	{
+		//body has already been converted
+		solverBodyIdA = body.getCompanionId();
+		btAssert(solverBodyIdA < m_tmpSolverBodyPool.size());
+	}
+	else
+	{
+		btRigidBody* rb = btRigidBody::upcast(&body);
+		//convert both active and kinematic objects (for their velocity)
+		if (rb && (rb->getInvMass() || rb->isKinematicObject()))
+		{
+			btAssert(0);
+		}
+		else
+		{
+			if (m_fixedBodyId < 0)
+			{
+				btAssert(0);
+			}
+			return m_fixedBodyId;
+			//			return 0;//assume first one is a fixed solver body
+		}
+	}
+
+	return solverBodyIdA;
+#endif  // BT_THREADSAFE
+}
+
 int btSequentialImpulseConstraintSolver::getOrInitSolverBody(btCollisionObject& body, btScalar timeStep)
 {
 #if BT_THREADSAFE
@@ -789,17 +1064,20 @@ int btSequentialImpulseConstraintSolver::getOrInitSolverBody(btCollisionObject&
 }
 #include <stdio.h>
 
-void btSequentialImpulseConstraintSolver::setupContactConstraint(btSolverConstraint& solverConstraint,
-																 int solverBodyIdA, int solverBodyIdB,
-																 btManifoldPoint& cp, const btContactSolverInfo& infoGlobal,
-																 btScalar& relaxation,
-																 const btVector3& rel_pos1, const btVector3& rel_pos2)
+
+
+void btSequentialImpulseConstraintSolver::setupContactConstraintInternal(btSISolverSingleIterationData& siData,
+	btSolverConstraint& solverConstraint,
+	int solverBodyIdA, int solverBodyIdB,
+	btManifoldPoint& cp, const btContactSolverInfo& infoGlobal,
+	btScalar& relaxation,
+	const btVector3& rel_pos1, const btVector3& rel_pos2)
 {
 	//	const btVector3& pos1 = cp.getPositionWorldOnA();
 	//	const btVector3& pos2 = cp.getPositionWorldOnB();
 
-	btSolverBody* bodyA = &m_tmpSolverBodyPool[solverBodyIdA];
-	btSolverBody* bodyB = &m_tmpSolverBodyPool[solverBodyIdB];
+	btSolverBody* bodyA = &siData.m_tmpSolverBodyPool[solverBodyIdA];
+	btSolverBody* bodyB = &siData.m_tmpSolverBodyPool[solverBodyIdB];
 
 	btRigidBody* rb0 = bodyA->m_originalBody;
 	btRigidBody* rb1 = bodyB->m_originalBody;
@@ -906,7 +1184,7 @@ void btSequentialImpulseConstraintSolver::setupContactConstraint(btSolverConstra
 
 		solverConstraint.m_friction = cp.m_combinedFriction;
 
-		restitution = restitutionCurve(rel_vel, cp.m_combinedRestitution, infoGlobal.m_restitutionVelocityThreshold);
+		restitution = btSequentialImpulseConstraintSolver::restitutionCurveInternal(rel_vel, cp.m_combinedRestitution, infoGlobal.m_restitutionVelocityThreshold);
 		if (restitution <= btScalar(0.))
 		{
 			restitution = 0.f;
@@ -920,7 +1198,7 @@ void btSequentialImpulseConstraintSolver::setupContactConstraint(btSolverConstra
 		if (rb0)
 			bodyA->internalApplyImpulse(solverConstraint.m_contactNormal1 * bodyA->internalGetInvMass(), solverConstraint.m_angularComponentA, solverConstraint.m_appliedImpulse);
 		if (rb1)
-			bodyB->internalApplyImpulse(-solverConstraint.m_contactNormal2 * bodyB->internalGetInvMass() , -solverConstraint.m_angularComponentB, -(btScalar)solverConstraint.m_appliedImpulse);
+			bodyB->internalApplyImpulse(-solverConstraint.m_contactNormal2 * bodyB->internalGetInvMass(), -solverConstraint.m_angularComponentB, -(btScalar)solverConstraint.m_appliedImpulse);
 	}
 	else
 	{
@@ -974,25 +1252,59 @@ void btSequentialImpulseConstraintSolver::setupContactConstraint(btSolverConstra
 	}
 }
 
-void btSequentialImpulseConstraintSolver::setFrictionConstraintImpulse(btSolverConstraint& solverConstraint,
-																	   int solverBodyIdA, int solverBodyIdB,
-																	   btManifoldPoint& cp, const btContactSolverInfo& infoGlobal)
+void btSequentialImpulseConstraintSolver::setupContactConstraint(btSolverConstraint& solverConstraint,
+	int solverBodyIdA, int solverBodyIdB,
+	btManifoldPoint& cp, const btContactSolverInfo& infoGlobal,
+	btScalar& relaxation,
+	const btVector3& rel_pos1, const btVector3& rel_pos2)
+{
+	btSISolverSingleIterationData siData(m_tmpSolverBodyPool,
+		m_tmpSolverContactConstraintPool,
+		m_tmpSolverNonContactConstraintPool,
+		m_tmpSolverContactFrictionConstraintPool,
+		m_tmpSolverContactRollingFrictionConstraintPool,
+		m_orderTmpConstraintPool,
+		m_orderNonContactConstraintPool,
+		m_orderFrictionConstraintPool,
+		m_tmpConstraintSizesPool,
+		m_resolveSingleConstraintRowGeneric,
+		m_resolveSingleConstraintRowLowerLimit,
+		m_resolveSplitPenetrationImpulse,
+		m_kinematicBodyUniqueIdToSolverBodyTable,
+		m_btSeed2,
+		m_fixedBodyId,
+		m_maxOverrideNumSolverIterations
+	);
+
+
+	setupContactConstraintInternal(siData, solverConstraint,
+		solverBodyIdA, solverBodyIdB,
+		cp, infoGlobal,
+		relaxation,
+		rel_pos1, rel_pos2);
+}
+
+
+void btSequentialImpulseConstraintSolver::setFrictionConstraintImpulseInternal(btAlignedObjectArray<btSolverBody>& tmpSolverBodyPool, btConstraintArray& tmpSolverContactFrictionConstraintPool,
+	btSolverConstraint& solverConstraint,
+	int solverBodyIdA, int solverBodyIdB,
+	btManifoldPoint& cp, const btContactSolverInfo& infoGlobal)
 {
-	btSolverBody* bodyA = &m_tmpSolverBodyPool[solverBodyIdA];
-	btSolverBody* bodyB = &m_tmpSolverBodyPool[solverBodyIdB];
+	btSolverBody* bodyA = &tmpSolverBodyPool[solverBodyIdA];
+	btSolverBody* bodyB = &tmpSolverBodyPool[solverBodyIdB];
 
 	btRigidBody* rb0 = bodyA->m_originalBody;
 	btRigidBody* rb1 = bodyB->m_originalBody;
 
 	{
-		btSolverConstraint& frictionConstraint1 = m_tmpSolverContactFrictionConstraintPool[solverConstraint.m_frictionIndex];
+		btSolverConstraint& frictionConstraint1 = tmpSolverContactFrictionConstraintPool[solverConstraint.m_frictionIndex];
 		if (infoGlobal.m_solverMode & SOLVER_USE_WARMSTARTING)
 		{
 			frictionConstraint1.m_appliedImpulse = cp.m_appliedImpulseLateral1 * infoGlobal.m_warmstartingFactor;
 			if (rb0)
-				bodyA->internalApplyImpulse(frictionConstraint1.m_contactNormal1 * rb0->getInvMass() , frictionConstraint1.m_angularComponentA, frictionConstraint1.m_appliedImpulse);
+				bodyA->internalApplyImpulse(frictionConstraint1.m_contactNormal1 * rb0->getInvMass(), frictionConstraint1.m_angularComponentA, frictionConstraint1.m_appliedImpulse);
 			if (rb1)
-				bodyB->internalApplyImpulse(-frictionConstraint1.m_contactNormal2 * rb1->getInvMass() , -frictionConstraint1.m_angularComponentB, -(btScalar)frictionConstraint1.m_appliedImpulse);
+				bodyB->internalApplyImpulse(-frictionConstraint1.m_contactNormal2 * rb1->getInvMass(), -frictionConstraint1.m_angularComponentB, -(btScalar)frictionConstraint1.m_appliedImpulse);
 		}
 		else
 		{
@@ -1002,7 +1314,7 @@ void btSequentialImpulseConstraintSolver::setFrictionConstraintImpulse(btSolverC
 
 	if ((infoGlobal.m_solverMode & SOLVER_USE_2_FRICTION_DIRECTIONS))
 	{
-		btSolverConstraint& frictionConstraint2 = m_tmpSolverContactFrictionConstraintPool[solverConstraint.m_frictionIndex + 1];
+		btSolverConstraint& frictionConstraint2 = tmpSolverContactFrictionConstraintPool[solverConstraint.m_frictionIndex + 1];
 		if (infoGlobal.m_solverMode & SOLVER_USE_WARMSTARTING)
 		{
 			frictionConstraint2.m_appliedImpulse = cp.m_appliedImpulseLateral2 * infoGlobal.m_warmstartingFactor;
@@ -1018,21 +1330,31 @@ void btSequentialImpulseConstraintSolver::setFrictionConstraintImpulse(btSolverC
 	}
 }
 
-void btSequentialImpulseConstraintSolver::convertContact(btPersistentManifold* manifold, const btContactSolverInfo& infoGlobal)
+void btSequentialImpulseConstraintSolver::setFrictionConstraintImpulse(btSolverConstraint& solverConstraint,
+	int solverBodyIdA, int solverBodyIdB,
+	btManifoldPoint& cp, const btContactSolverInfo& infoGlobal)
+{
+	setFrictionConstraintImpulseInternal(m_tmpSolverBodyPool, m_tmpSolverContactFrictionConstraintPool,
+		solverConstraint,
+		solverBodyIdA, solverBodyIdB,
+		cp, infoGlobal);
+
+}
+void btSequentialImpulseConstraintSolver::convertContactInternal(btSISolverSingleIterationData& siData, btPersistentManifold* manifold, const btContactSolverInfo& infoGlobal)
 {
 	btCollisionObject *colObj0 = 0, *colObj1 = 0;
 
 	colObj0 = (btCollisionObject*)manifold->getBody0();
 	colObj1 = (btCollisionObject*)manifold->getBody1();
 
-	int solverBodyIdA = getOrInitSolverBody(*colObj0, infoGlobal.m_timeStep);
-	int solverBodyIdB = getOrInitSolverBody(*colObj1, infoGlobal.m_timeStep);
+	int solverBodyIdA = siData.getOrInitSolverBody(*colObj0, infoGlobal.m_timeStep);
+	int solverBodyIdB = siData.getOrInitSolverBody(*colObj1, infoGlobal.m_timeStep);
 
 	//	btRigidBody* bodyA = btRigidBody::upcast(colObj0);
 	//	btRigidBody* bodyB = btRigidBody::upcast(colObj1);
 
-	btSolverBody* solverBodyA = &m_tmpSolverBodyPool[solverBodyIdA];
-	btSolverBody* solverBodyB = &m_tmpSolverBodyPool[solverBodyIdB];
+	btSolverBody* solverBodyA = &siData.m_tmpSolverBodyPool[solverBodyIdA];
+	btSolverBody* solverBodyB = &siData.m_tmpSolverBodyPool[solverBodyIdB];
 
 	///avoid collision response between two static objects
 	if (!solverBodyA || (solverBodyA->m_invMass.fuzzyZero() && (!solverBodyB || solverBodyB->m_invMass.fuzzyZero())))
@@ -1049,8 +1371,8 @@ void btSequentialImpulseConstraintSolver::convertContact(btPersistentManifold* m
 			btVector3 rel_pos2;
 			btScalar relaxation;
 
-			int frictionIndex = m_tmpSolverContactConstraintPool.size();
-			btSolverConstraint& solverConstraint = m_tmpSolverContactConstraintPool.expandNonInitializing();
+			int frictionIndex = siData.m_tmpSolverContactConstraintPool.size();
+			btSolverConstraint& solverConstraint = siData.m_tmpSolverContactConstraintPool.expandNonInitializing();
 			solverConstraint.m_solverBodyIdA = solverBodyIdA;
 			solverConstraint.m_solverBodyIdB = solverBodyIdB;
 
@@ -1071,16 +1393,20 @@ void btSequentialImpulseConstraintSolver::convertContact(btPersistentManifold* m
 			btVector3 vel = vel1 - vel2;
 			btScalar rel_vel = cp.m_normalWorldOnB.dot(vel);
 
-			setupContactConstraint(solverConstraint, solverBodyIdA, solverBodyIdB, cp, infoGlobal, relaxation, rel_pos1, rel_pos2);
+			setupContactConstraintInternal(siData, solverConstraint, solverBodyIdA, solverBodyIdB, cp, infoGlobal, relaxation, rel_pos1, rel_pos2);
 
 			/////setup the friction constraints
 
-			solverConstraint.m_frictionIndex = m_tmpSolverContactFrictionConstraintPool.size();
+			solverConstraint.m_frictionIndex = siData.m_tmpSolverContactFrictionConstraintPool.size();
 
 			if ((cp.m_combinedRollingFriction > 0.f) && (rollingFriction > 0))
 			{
 				{
-					addTorsionalFrictionConstraint(cp.m_normalWorldOnB, solverBodyIdA, solverBodyIdB, frictionIndex, cp, cp.m_combinedSpinningFriction, rel_pos1, rel_pos2, colObj0, colObj1, relaxation);
+
+					btSequentialImpulseConstraintSolver::addTorsionalFrictionConstraintInternal(siData.m_tmpSolverBodyPool,
+						siData.m_tmpSolverContactRollingFrictionConstraintPool,
+						cp.m_normalWorldOnB, solverBodyIdA, solverBodyIdB, frictionIndex, cp, cp.m_combinedSpinningFriction, rel_pos1, rel_pos2, colObj0, colObj1, relaxation);
+
 					btVector3 axis0, axis1;
 					btPlaneSpace1(cp.m_normalWorldOnB, axis0, axis1);
 					axis0.normalize();
@@ -1091,11 +1417,17 @@ void btSequentialImpulseConstraintSolver::convertContact(btPersistentManifold* m
 					applyAnisotropicFriction(colObj0, axis1, btCollisionObject::CF_ANISOTROPIC_ROLLING_FRICTION);
 					applyAnisotropicFriction(colObj1, axis1, btCollisionObject::CF_ANISOTROPIC_ROLLING_FRICTION);
 					if (axis0.length() > 0.001)
-						addTorsionalFrictionConstraint(axis0, solverBodyIdA, solverBodyIdB, frictionIndex, cp,
-													   cp.m_combinedRollingFriction, rel_pos1, rel_pos2, colObj0, colObj1, relaxation);
+					{
+						btSequentialImpulseConstraintSolver::addTorsionalFrictionConstraintInternal(siData.m_tmpSolverBodyPool,
+							siData.m_tmpSolverContactRollingFrictionConstraintPool, axis0, solverBodyIdA, solverBodyIdB, frictionIndex, cp,
+							cp.m_combinedRollingFriction, rel_pos1, rel_pos2, colObj0, colObj1, relaxation);
+					}
 					if (axis1.length() > 0.001)
-						addTorsionalFrictionConstraint(axis1, solverBodyIdA, solverBodyIdB, frictionIndex, cp,
-													   cp.m_combinedRollingFriction, rel_pos1, rel_pos2, colObj0, colObj1, relaxation);
+					{
+						btSequentialImpulseConstraintSolver::addTorsionalFrictionConstraintInternal(siData.m_tmpSolverBodyPool,
+							siData.m_tmpSolverContactRollingFrictionConstraintPool, axis1, solverBodyIdA, solverBodyIdB, frictionIndex, cp,
+							cp.m_combinedRollingFriction, rel_pos1, rel_pos2, colObj0, colObj1, relaxation);
+					}
 				}
 			}
 
@@ -1124,7 +1456,8 @@ void btSequentialImpulseConstraintSolver::convertContact(btPersistentManifold* m
 					cp.m_lateralFrictionDir1 *= 1.f / btSqrt(lat_rel_vel);
 					applyAnisotropicFriction(colObj0, cp.m_lateralFrictionDir1, btCollisionObject::CF_ANISOTROPIC_FRICTION);
 					applyAnisotropicFriction(colObj1, cp.m_lateralFrictionDir1, btCollisionObject::CF_ANISOTROPIC_FRICTION);
-					addFrictionConstraint(cp.m_lateralFrictionDir1, solverBodyIdA, solverBodyIdB, frictionIndex, cp, rel_pos1, rel_pos2, colObj0, colObj1, relaxation, infoGlobal);
+					btSequentialImpulseConstraintSolver::addFrictionConstraintInternal(siData.m_tmpSolverBodyPool, siData.m_tmpSolverContactFrictionConstraintPool,
+						cp.m_lateralFrictionDir1, solverBodyIdA, solverBodyIdB, frictionIndex, cp, rel_pos1, rel_pos2, colObj0, colObj1, relaxation, infoGlobal);
 
 					if ((infoGlobal.m_solverMode & SOLVER_USE_2_FRICTION_DIRECTIONS))
 					{
@@ -1132,7 +1465,8 @@ void btSequentialImpulseConstraintSolver::convertContact(btPersistentManifold* m
 						cp.m_lateralFrictionDir2.normalize();  //??
 						applyAnisotropicFriction(colObj0, cp.m_lateralFrictionDir2, btCollisionObject::CF_ANISOTROPIC_FRICTION);
 						applyAnisotropicFriction(colObj1, cp.m_lateralFrictionDir2, btCollisionObject::CF_ANISOTROPIC_FRICTION);
-						addFrictionConstraint(cp.m_lateralFrictionDir2, solverBodyIdA, solverBodyIdB, frictionIndex, cp, rel_pos1, rel_pos2, colObj0, colObj1, relaxation, infoGlobal);
+						btSequentialImpulseConstraintSolver::addFrictionConstraintInternal(siData.m_tmpSolverBodyPool, siData.m_tmpSolverContactFrictionConstraintPool,
+							cp.m_lateralFrictionDir2, solverBodyIdA, solverBodyIdB, frictionIndex, cp, rel_pos1, rel_pos2, colObj0, colObj1, relaxation, infoGlobal);
 					}
 				}
 				else
@@ -1141,13 +1475,15 @@ void btSequentialImpulseConstraintSolver::convertContact(btPersistentManifold* m
 
 					applyAnisotropicFriction(colObj0, cp.m_lateralFrictionDir1, btCollisionObject::CF_ANISOTROPIC_FRICTION);
 					applyAnisotropicFriction(colObj1, cp.m_lateralFrictionDir1, btCollisionObject::CF_ANISOTROPIC_FRICTION);
-					addFrictionConstraint(cp.m_lateralFrictionDir1, solverBodyIdA, solverBodyIdB, frictionIndex, cp, rel_pos1, rel_pos2, colObj0, colObj1, relaxation, infoGlobal);
+					btSequentialImpulseConstraintSolver::addFrictionConstraintInternal(siData.m_tmpSolverBodyPool, siData.m_tmpSolverContactFrictionConstraintPool,
+						cp.m_lateralFrictionDir1, solverBodyIdA, solverBodyIdB, frictionIndex, cp, rel_pos1, rel_pos2, colObj0, colObj1, relaxation, infoGlobal);
 
 					if ((infoGlobal.m_solverMode & SOLVER_USE_2_FRICTION_DIRECTIONS))
 					{
 						applyAnisotropicFriction(colObj0, cp.m_lateralFrictionDir2, btCollisionObject::CF_ANISOTROPIC_FRICTION);
 						applyAnisotropicFriction(colObj1, cp.m_lateralFrictionDir2, btCollisionObject::CF_ANISOTROPIC_FRICTION);
-						addFrictionConstraint(cp.m_lateralFrictionDir2, solverBodyIdA, solverBodyIdB, frictionIndex, cp, rel_pos1, rel_pos2, colObj0, colObj1, relaxation, infoGlobal);
+						btSequentialImpulseConstraintSolver::addFrictionConstraintInternal(siData.m_tmpSolverBodyPool, siData.m_tmpSolverContactFrictionConstraintPool,
+							cp.m_lateralFrictionDir2, solverBodyIdA, solverBodyIdB, frictionIndex, cp, rel_pos1, rel_pos2, colObj0, colObj1, relaxation, infoGlobal);
 					}
 
 					if ((infoGlobal.m_solverMode & SOLVER_USE_2_FRICTION_DIRECTIONS) && (infoGlobal.m_solverMode & SOLVER_DISABLE_VELOCITY_DEPENDENT_FRICTION_DIRECTION))
@@ -1158,16 +1494,44 @@ void btSequentialImpulseConstraintSolver::convertContact(btPersistentManifold* m
 			}
 			else
 			{
-				addFrictionConstraint(cp.m_lateralFrictionDir1, solverBodyIdA, solverBodyIdB, frictionIndex, cp, rel_pos1, rel_pos2, colObj0, colObj1, relaxation, infoGlobal, cp.m_contactMotion1, cp.m_frictionCFM);
+				btSequentialImpulseConstraintSolver::addFrictionConstraintInternal(siData.m_tmpSolverBodyPool, siData.m_tmpSolverContactFrictionConstraintPool,
+					cp.m_lateralFrictionDir1, solverBodyIdA, solverBodyIdB, frictionIndex, cp, rel_pos1, rel_pos2, colObj0, colObj1, relaxation, infoGlobal, cp.m_contactMotion1, cp.m_frictionCFM);
 
 				if ((infoGlobal.m_solverMode & SOLVER_USE_2_FRICTION_DIRECTIONS))
-					addFrictionConstraint(cp.m_lateralFrictionDir2, solverBodyIdA, solverBodyIdB, frictionIndex, cp, rel_pos1, rel_pos2, colObj0, colObj1, relaxation, infoGlobal, cp.m_contactMotion2, cp.m_frictionCFM);
+				{
+					btSequentialImpulseConstraintSolver::addFrictionConstraintInternal(siData.m_tmpSolverBodyPool, siData.m_tmpSolverContactFrictionConstraintPool,
+						cp.m_lateralFrictionDir2, solverBodyIdA, solverBodyIdB, frictionIndex, cp, rel_pos1, rel_pos2, colObj0, colObj1, relaxation, infoGlobal, cp.m_contactMotion2, cp.m_frictionCFM);
+				}
 			}
-			setFrictionConstraintImpulse(solverConstraint, solverBodyIdA, solverBodyIdB, cp, infoGlobal);
+			btSequentialImpulseConstraintSolver::setFrictionConstraintImpulseInternal(
+				siData.m_tmpSolverBodyPool, siData.m_tmpSolverContactFrictionConstraintPool,
+				solverConstraint, solverBodyIdA, solverBodyIdB, cp, infoGlobal);
 		}
 	}
 }
 
+void btSequentialImpulseConstraintSolver::convertContact(btPersistentManifold* manifold, const btContactSolverInfo& infoGlobal)
+{
+	btSISolverSingleIterationData siData(m_tmpSolverBodyPool,
+		m_tmpSolverContactConstraintPool,
+		m_tmpSolverNonContactConstraintPool,
+		m_tmpSolverContactFrictionConstraintPool,
+		m_tmpSolverContactRollingFrictionConstraintPool,
+		m_orderTmpConstraintPool,
+		m_orderNonContactConstraintPool,
+		m_orderFrictionConstraintPool,
+		m_tmpConstraintSizesPool,
+		m_resolveSingleConstraintRowGeneric,
+		m_resolveSingleConstraintRowLowerLimit,
+		m_resolveSplitPenetrationImpulse,
+		m_kinematicBodyUniqueIdToSolverBodyTable,
+		m_btSeed2,
+		m_fixedBodyId,
+		m_maxOverrideNumSolverIterations);
+
+	btSequentialImpulseConstraintSolver::convertContactInternal(siData, manifold, infoGlobal);
+}
+
 void btSequentialImpulseConstraintSolver::convertContacts(btPersistentManifold** manifoldPtr, int numManifolds, const btContactSolverInfo& infoGlobal)
 {
 	int i;
@@ -1181,22 +1545,24 @@ void btSequentialImpulseConstraintSolver::convertContacts(btPersistentManifold**
 	}
 }
 
-void btSequentialImpulseConstraintSolver::convertJoint(btSolverConstraint* currentConstraintRow,
-													   btTypedConstraint* constraint,
-													   const btTypedConstraint::btConstraintInfo1& info1,
-													   int solverBodyIdA,
-													   int solverBodyIdB,
-													   const btContactSolverInfo& infoGlobal)
+void btSequentialImpulseConstraintSolver::convertJointInternal(btAlignedObjectArray<btSolverBody>& tmpSolverBodyPool,
+	int& maxOverrideNumSolverIterations,
+	btSolverConstraint* currentConstraintRow,
+	btTypedConstraint* constraint,
+	const btTypedConstraint::btConstraintInfo1& info1,
+	int solverBodyIdA,
+	int solverBodyIdB,
+	const btContactSolverInfo& infoGlobal)
 {
 	const btRigidBody& rbA = constraint->getRigidBodyA();
 	const btRigidBody& rbB = constraint->getRigidBodyB();
 
-	const btSolverBody* bodyAPtr = &m_tmpSolverBodyPool[solverBodyIdA];
-	const btSolverBody* bodyBPtr = &m_tmpSolverBodyPool[solverBodyIdB];
+	const btSolverBody* bodyAPtr = &tmpSolverBodyPool[solverBodyIdA];
+	const btSolverBody* bodyBPtr = &tmpSolverBodyPool[solverBodyIdB];
 
 	int overrideNumSolverIterations = constraint->getOverrideNumSolverIterations() > 0 ? constraint->getOverrideNumSolverIterations() : infoGlobal.m_numIterations;
-	if (overrideNumSolverIterations > m_maxOverrideNumSolverIterations)
-		m_maxOverrideNumSolverIterations = overrideNumSolverIterations;
+	if (overrideNumSolverIterations > maxOverrideNumSolverIterations)
+		maxOverrideNumSolverIterations = overrideNumSolverIterations;
 
 	for (int j = 0; j < info1.m_numConstraintRows; j++)
 	{
@@ -1236,7 +1602,7 @@ void btSequentialImpulseConstraintSolver::convertJoint(btSolverConstraint* curre
 	info2.m_J2linearAxis = currentConstraintRow->m_contactNormal2;
 	info2.m_J2angularAxis = currentConstraintRow->m_relpos2CrossNormal;
 	info2.rowskip = sizeof(btSolverConstraint) / sizeof(btScalar);  //check this
-	///the size of btSolverConstraint needs be a multiple of btScalar
+																	///the size of btSolverConstraint needs be a multiple of btScalar
 	btAssert(info2.rowskip * sizeof(btScalar) == sizeof(btSolverConstraint));
 	info2.m_constraintError = &currentConstraintRow->m_rhs;
 	currentConstraintRow->m_cfm = infoGlobal.m_globalCfm;
@@ -1313,7 +1679,16 @@ void btSequentialImpulseConstraintSolver::convertJoint(btSolverConstraint* curre
 	}
 }
 
-void btSequentialImpulseConstraintSolver::convertJoints(btTypedConstraint** constraints, int numConstraints, const btContactSolverInfo& infoGlobal)
+void btSequentialImpulseConstraintSolver::convertJoint(btSolverConstraint* currentConstraintRow,
+	btTypedConstraint* constraint,
+	const btTypedConstraint::btConstraintInfo1& info1,
+	int solverBodyIdA,
+	int solverBodyIdB,
+	const btContactSolverInfo& infoGlobal)
+{
+}
+
+void btSequentialImpulseConstraintSolver::convertJointsInternal(btSISolverSingleIterationData& siData, btTypedConstraint** constraints, int numConstraints, const btContactSolverInfo& infoGlobal)
 {
 	BT_PROFILE("convertJoints");
 	for (int j = 0; j < numConstraints; j++)
@@ -1325,11 +1700,11 @@ void btSequentialImpulseConstraintSolver::convertJoints(btTypedConstraint** cons
 
 	int totalNumRows = 0;
 
-	m_tmpConstraintSizesPool.resizeNoInitialize(numConstraints);
+	siData.m_tmpConstraintSizesPool.resizeNoInitialize(numConstraints);
 	//calculate the total number of contraint rows
 	for (int i = 0; i < numConstraints; i++)
 	{
-		btTypedConstraint::btConstraintInfo1& info1 = m_tmpConstraintSizesPool[i];
+		btTypedConstraint::btConstraintInfo1& info1 = siData.m_tmpConstraintSizesPool[i];
 		btJointFeedback* fb = constraints[i]->getJointFeedback();
 		if (fb)
 		{
@@ -1350,34 +1725,58 @@ void btSequentialImpulseConstraintSolver::convertJoints(btTypedConstraint** cons
 		}
 		totalNumRows += info1.m_numConstraintRows;
 	}
-	m_tmpSolverNonContactConstraintPool.resizeNoInitialize(totalNumRows);
+	siData.m_tmpSolverNonContactConstraintPool.resizeNoInitialize(totalNumRows);
 
 	///setup the btSolverConstraints
 	int currentRow = 0;
 
 	for (int i = 0; i < numConstraints; i++)
 	{
-		const btTypedConstraint::btConstraintInfo1& info1 = m_tmpConstraintSizesPool[i];
+		const btTypedConstraint::btConstraintInfo1& info1 = siData.m_tmpConstraintSizesPool[i];
 
 		if (info1.m_numConstraintRows)
 		{
 			btAssert(currentRow < totalNumRows);
 
-			btSolverConstraint* currentConstraintRow = &m_tmpSolverNonContactConstraintPool[currentRow];
+			btSolverConstraint* currentConstraintRow = &siData.m_tmpSolverNonContactConstraintPool[currentRow];
 			btTypedConstraint* constraint = constraints[i];
 			btRigidBody& rbA = constraint->getRigidBodyA();
 			btRigidBody& rbB = constraint->getRigidBodyB();
 
-			int solverBodyIdA = getOrInitSolverBody(rbA, infoGlobal.m_timeStep);
-			int solverBodyIdB = getOrInitSolverBody(rbB, infoGlobal.m_timeStep);
+			int solverBodyIdA = siData.getOrInitSolverBody(rbA, infoGlobal.m_timeStep);
+			int solverBodyIdB = siData.getOrInitSolverBody(rbB, infoGlobal.m_timeStep);
 
-			convertJoint(currentConstraintRow, constraint, info1, solverBodyIdA, solverBodyIdB, infoGlobal);
+			convertJointInternal(siData.m_tmpSolverBodyPool, siData.m_maxOverrideNumSolverIterations,
+				currentConstraintRow, constraint, info1, solverBodyIdA, solverBodyIdB, infoGlobal);
 		}
 		currentRow += info1.m_numConstraintRows;
 	}
 }
 
-void btSequentialImpulseConstraintSolver::convertBodies(btCollisionObject** bodies, int numBodies, const btContactSolverInfo& infoGlobal)
+void btSequentialImpulseConstraintSolver::convertJoints(btTypedConstraint** constraints, int numConstraints, const btContactSolverInfo& infoGlobal)
+{
+	btSISolverSingleIterationData siData(m_tmpSolverBodyPool,
+		m_tmpSolverContactConstraintPool,
+		m_tmpSolverNonContactConstraintPool,
+		m_tmpSolverContactFrictionConstraintPool,
+		m_tmpSolverContactRollingFrictionConstraintPool,
+		m_orderTmpConstraintPool,
+		m_orderNonContactConstraintPool,
+		m_orderFrictionConstraintPool,
+		m_tmpConstraintSizesPool,
+		m_resolveSingleConstraintRowGeneric,
+		m_resolveSingleConstraintRowLowerLimit,
+		m_resolveSplitPenetrationImpulse,
+		m_kinematicBodyUniqueIdToSolverBodyTable,
+		m_btSeed2,
+		m_fixedBodyId,
+		m_maxOverrideNumSolverIterations);
+
+	convertJointsInternal(siData, constraints, numConstraints, infoGlobal);
+}
+
+
+void btSequentialImpulseConstraintSolver::convertBodiesInternal(btSISolverSingleIterationData& siData, btCollisionObject** bodies, int numBodies, const btContactSolverInfo& infoGlobal)
 {
 	BT_PROFILE("convertBodies");
 	for (int i = 0; i < numBodies; i++)
@@ -1385,23 +1784,23 @@ void btSequentialImpulseConstraintSolver::convertBodies(btCollisionObject** bodi
 		bodies[i]->setCompanionId(-1);
 	}
 #if BT_THREADSAFE
-	m_kinematicBodyUniqueIdToSolverBodyTable.resize(0);
+	siData.m_kinematicBodyUniqueIdToSolverBodyTable.resize(0);
 #endif  // BT_THREADSAFE
 
-	m_tmpSolverBodyPool.reserve(numBodies + 1);
-	m_tmpSolverBodyPool.resize(0);
+	siData.m_tmpSolverBodyPool.reserve(numBodies + 1);
+	siData.m_tmpSolverBodyPool.resize(0);
 
 	//btSolverBody& fixedBody = m_tmpSolverBodyPool.expand();
 	//initSolverBody(&fixedBody,0);
 
 	for (int i = 0; i < numBodies; i++)
 	{
-		int bodyId = getOrInitSolverBody(*bodies[i], infoGlobal.m_timeStep);
+		int bodyId = siData.getOrInitSolverBody(*bodies[i], infoGlobal.m_timeStep);
 
 		btRigidBody* body = btRigidBody::upcast(bodies[i]);
 		if (body && body->getInvMass())
 		{
-			btSolverBody& solverBody = m_tmpSolverBodyPool[bodyId];
+			btSolverBody& solverBody = siData.m_tmpSolverBodyPool[bodyId];
 			btVector3 gyroForce(0, 0, 0);
 			if (body->getFlags() & BT_ENABLE_GYROSCOPIC_FORCE_EXPLICIT)
 			{
@@ -1422,6 +1821,29 @@ void btSequentialImpulseConstraintSolver::convertBodies(btCollisionObject** bodi
 	}
 }
 
+
+void btSequentialImpulseConstraintSolver::convertBodies(btCollisionObject** bodies, int numBodies, const btContactSolverInfo& infoGlobal)
+{
+	btSISolverSingleIterationData siData(m_tmpSolverBodyPool,
+		m_tmpSolverContactConstraintPool,
+		m_tmpSolverNonContactConstraintPool,
+		m_tmpSolverContactFrictionConstraintPool,
+		m_tmpSolverContactRollingFrictionConstraintPool,
+		m_orderTmpConstraintPool,
+		m_orderNonContactConstraintPool,
+		m_orderFrictionConstraintPool,
+		m_tmpConstraintSizesPool,
+		m_resolveSingleConstraintRowGeneric,
+		m_resolveSingleConstraintRowLowerLimit,
+		m_resolveSplitPenetrationImpulse,
+		m_kinematicBodyUniqueIdToSolverBodyTable,
+		m_btSeed2,
+		m_fixedBodyId,
+		m_maxOverrideNumSolverIterations);
+
+	convertBodiesInternal(siData, bodies, numBodies, infoGlobal);
+}
+
 btScalar btSequentialImpulseConstraintSolver::solveGroupCacheFriendlySetup(btCollisionObject** bodies, int numBodies, btPersistentManifold** manifoldPtr, int numManifolds, btTypedConstraint** constraints, int numConstraints, const btContactSolverInfo& infoGlobal, btIDebugDraw* debugDrawer)
 {
 	m_fixedBodyId = -1;
@@ -1545,14 +1967,14 @@ btScalar btSequentialImpulseConstraintSolver::solveGroupCacheFriendlySetup(btCol
 	return 0.f;
 }
 
-btScalar btSequentialImpulseConstraintSolver::solveSingleIteration(int iteration, btCollisionObject** /*bodies */, int /*numBodies*/, btPersistentManifold** /*manifoldPtr*/, int /*numManifolds*/, btTypedConstraint** constraints, int numConstraints, const btContactSolverInfo& infoGlobal, btIDebugDraw* /*debugDrawer*/)
+btScalar btSequentialImpulseConstraintSolver::solveSingleIterationInternal(btSISolverSingleIterationData& siData, int iteration, btTypedConstraint** constraints, int numConstraints, const btContactSolverInfo& infoGlobal)
 {
 	BT_PROFILE("solveSingleIteration");
 	btScalar leastSquaresResidual = 0.f;
 
-	int numNonContactPool = m_tmpSolverNonContactConstraintPool.size();
-	int numConstraintPool = m_tmpSolverContactConstraintPool.size();
-	int numFrictionPool = m_tmpSolverContactFrictionConstraintPool.size();
+	int numNonContactPool = siData.m_tmpSolverNonContactConstraintPool.size();
+	int numConstraintPool = siData.m_tmpSolverContactConstraintPool.size();
+	int numFrictionPool = siData.m_tmpSolverContactFrictionConstraintPool.size();
 
 	if (infoGlobal.m_solverMode & SOLVER_RANDMIZE_ORDER)
 	{
@@ -1560,10 +1982,10 @@ btScalar btSequentialImpulseConstraintSolver::solveSingleIteration(int iteration
 		{
 			for (int j = 0; j < numNonContactPool; ++j)
 			{
-				int tmp = m_orderNonContactConstraintPool[j];
-				int swapi = btRandInt2(j + 1);
-				m_orderNonContactConstraintPool[j] = m_orderNonContactConstraintPool[swapi];
-				m_orderNonContactConstraintPool[swapi] = tmp;
+				int tmp = siData.m_orderNonContactConstraintPool[j];
+				int swapi = btRandInt2a(j + 1, siData.m_seed);
+				siData.m_orderNonContactConstraintPool[j] = siData.m_orderNonContactConstraintPool[swapi];
+				siData.m_orderNonContactConstraintPool[swapi] = tmp;
 			}
 
 			//contact/friction constraints are not solved more than
@@ -1571,30 +1993,30 @@ btScalar btSequentialImpulseConstraintSolver::solveSingleIteration(int iteration
 			{
 				for (int j = 0; j < numConstraintPool; ++j)
 				{
-					int tmp = m_orderTmpConstraintPool[j];
-					int swapi = btRandInt2(j + 1);
-					m_orderTmpConstraintPool[j] = m_orderTmpConstraintPool[swapi];
-					m_orderTmpConstraintPool[swapi] = tmp;
+					int tmp = siData.m_orderTmpConstraintPool[j];
+					int swapi = btRandInt2a(j + 1, siData.m_seed);
+					siData.m_orderTmpConstraintPool[j] = siData.m_orderTmpConstraintPool[swapi];
+					siData.m_orderTmpConstraintPool[swapi] = tmp;
 				}
 
 				for (int j = 0; j < numFrictionPool; ++j)
 				{
-					int tmp = m_orderFrictionConstraintPool[j];
-					int swapi = btRandInt2(j + 1);
-					m_orderFrictionConstraintPool[j] = m_orderFrictionConstraintPool[swapi];
-					m_orderFrictionConstraintPool[swapi] = tmp;
+					int tmp = siData.m_orderFrictionConstraintPool[j];
+					int swapi = btRandInt2a(j + 1, siData.m_seed);
+					siData.m_orderFrictionConstraintPool[j] = siData.m_orderFrictionConstraintPool[swapi];
+					siData.m_orderFrictionConstraintPool[swapi] = tmp;
 				}
 			}
 		}
 	}
 
 	///solve all joint constraints
-	for (int j = 0; j < m_tmpSolverNonContactConstraintPool.size(); j++)
+	for (int j = 0; j < siData.m_tmpSolverNonContactConstraintPool.size(); j++)
 	{
-		btSolverConstraint& constraint = m_tmpSolverNonContactConstraintPool[m_orderNonContactConstraintPool[j]];
+		btSolverConstraint& constraint = siData.m_tmpSolverNonContactConstraintPool[siData.m_orderNonContactConstraintPool[j]];
 		if (iteration < constraint.m_overrideNumSolverIterations)
 		{
-			btScalar residual = resolveSingleConstraintRowGeneric(m_tmpSolverBodyPool[constraint.m_solverBodyIdA], m_tmpSolverBodyPool[constraint.m_solverBodyIdB], constraint);
+			btScalar residual = siData.m_resolveSingleConstraintRowGeneric(siData.m_tmpSolverBodyPool[constraint.m_solverBodyIdA], siData.m_tmpSolverBodyPool[constraint.m_solverBodyIdB], constraint);
 			leastSquaresResidual = btMax(leastSquaresResidual, residual * residual);
 		}
 	}
@@ -1605,10 +2027,10 @@ btScalar btSequentialImpulseConstraintSolver::solveSingleIteration(int iteration
 		{
 			if (constraints[j]->isEnabled())
 			{
-				int bodyAid = getOrInitSolverBody(constraints[j]->getRigidBodyA(), infoGlobal.m_timeStep);
-				int bodyBid = getOrInitSolverBody(constraints[j]->getRigidBodyB(), infoGlobal.m_timeStep);
-				btSolverBody& bodyA = m_tmpSolverBodyPool[bodyAid];
-				btSolverBody& bodyB = m_tmpSolverBodyPool[bodyBid];
+				int bodyAid = siData.getSolverBody(constraints[j]->getRigidBodyA());
+				int bodyBid = siData.getSolverBody(constraints[j]->getRigidBodyB());
+				btSolverBody& bodyA = siData.m_tmpSolverBodyPool[bodyAid];
+				btSolverBody& bodyB = siData.m_tmpSolverBodyPool[bodyBid];
 				constraints[j]->solveConstraintObsolete(bodyA, bodyB, infoGlobal.m_timeStep);
 			}
 		}
@@ -1616,7 +2038,7 @@ btScalar btSequentialImpulseConstraintSolver::solveSingleIteration(int iteration
 		///solve all contact constraints
 		if (infoGlobal.m_solverMode & SOLVER_INTERLEAVE_CONTACT_AND_FRICTION_CONSTRAINTS)
 		{
-			int numPoolConstraints = m_tmpSolverContactConstraintPool.size();
+			int numPoolConstraints = siData.m_tmpSolverContactConstraintPool.size();
 			int multiplier = (infoGlobal.m_solverMode & SOLVER_USE_2_FRICTION_DIRECTIONS) ? 2 : 1;
 
 			for (int c = 0; c < numPoolConstraints; c++)
@@ -1624,8 +2046,8 @@ btScalar btSequentialImpulseConstraintSolver::solveSingleIteration(int iteration
 				btScalar totalImpulse = 0;
 
 				{
-					const btSolverConstraint& solveManifold = m_tmpSolverContactConstraintPool[m_orderTmpConstraintPool[c]];
-					btScalar residual = resolveSingleConstraintRowLowerLimit(m_tmpSolverBodyPool[solveManifold.m_solverBodyIdA], m_tmpSolverBodyPool[solveManifold.m_solverBodyIdB], solveManifold);
+					const btSolverConstraint& solveManifold = siData.m_tmpSolverContactConstraintPool[siData.m_orderTmpConstraintPool[c]];
+					btScalar residual = siData.m_resolveSingleConstraintRowLowerLimit(siData.m_tmpSolverBodyPool[solveManifold.m_solverBodyIdA], siData.m_tmpSolverBodyPool[solveManifold.m_solverBodyIdB], solveManifold);
 					leastSquaresResidual = btMax(leastSquaresResidual, residual * residual);
 
 					totalImpulse = solveManifold.m_appliedImpulse;
@@ -1634,28 +2056,28 @@ btScalar btSequentialImpulseConstraintSolver::solveSingleIteration(int iteration
 				if (applyFriction)
 				{
 					{
-						btSolverConstraint& solveManifold = m_tmpSolverContactFrictionConstraintPool[m_orderFrictionConstraintPool[c * multiplier]];
+						btSolverConstraint& solveManifold = siData.m_tmpSolverContactFrictionConstraintPool[siData.m_orderFrictionConstraintPool[c * multiplier]];
 
 						if (totalImpulse > btScalar(0))
 						{
 							solveManifold.m_lowerLimit = -(solveManifold.m_friction * totalImpulse);
 							solveManifold.m_upperLimit = solveManifold.m_friction * totalImpulse;
 
-							btScalar residual = resolveSingleConstraintRowGeneric(m_tmpSolverBodyPool[solveManifold.m_solverBodyIdA], m_tmpSolverBodyPool[solveManifold.m_solverBodyIdB], solveManifold);
+							btScalar residual = siData.m_resolveSingleConstraintRowGeneric(siData.m_tmpSolverBodyPool[solveManifold.m_solverBodyIdA], siData.m_tmpSolverBodyPool[solveManifold.m_solverBodyIdB], solveManifold);
 							leastSquaresResidual = btMax(leastSquaresResidual, residual * residual);
 						}
 					}
 
 					if (infoGlobal.m_solverMode & SOLVER_USE_2_FRICTION_DIRECTIONS)
 					{
-						btSolverConstraint& solveManifold = m_tmpSolverContactFrictionConstraintPool[m_orderFrictionConstraintPool[c * multiplier + 1]];
+						btSolverConstraint& solveManifold = siData.m_tmpSolverContactFrictionConstraintPool[siData.m_orderFrictionConstraintPool[c * multiplier + 1]];
 
 						if (totalImpulse > btScalar(0))
 						{
 							solveManifold.m_lowerLimit = -(solveManifold.m_friction * totalImpulse);
 							solveManifold.m_upperLimit = solveManifold.m_friction * totalImpulse;
 
-							btScalar residual = resolveSingleConstraintRowGeneric(m_tmpSolverBodyPool[solveManifold.m_solverBodyIdA], m_tmpSolverBodyPool[solveManifold.m_solverBodyIdB], solveManifold);
+							btScalar residual = siData.m_resolveSingleConstraintRowGeneric(siData.m_tmpSolverBodyPool[solveManifold.m_solverBodyIdA], siData.m_tmpSolverBodyPool[solveManifold.m_solverBodyIdB], solveManifold);
 							leastSquaresResidual = btMax(leastSquaresResidual, residual * residual);
 						}
 					}
@@ -1665,40 +2087,40 @@ btScalar btSequentialImpulseConstraintSolver::solveSingleIteration(int iteration
 		else  //SOLVER_INTERLEAVE_CONTACT_AND_FRICTION_CONSTRAINTS
 		{
 			//solve the friction constraints after all contact constraints, don't interleave them
-			int numPoolConstraints = m_tmpSolverContactConstraintPool.size();
+			int numPoolConstraints = siData.m_tmpSolverContactConstraintPool.size();
 			int j;
 
 			for (j = 0; j < numPoolConstraints; j++)
 			{
-				const btSolverConstraint& solveManifold = m_tmpSolverContactConstraintPool[m_orderTmpConstraintPool[j]];
-				btScalar residual = resolveSingleConstraintRowLowerLimit(m_tmpSolverBodyPool[solveManifold.m_solverBodyIdA], m_tmpSolverBodyPool[solveManifold.m_solverBodyIdB], solveManifold);
+				const btSolverConstraint& solveManifold = siData.m_tmpSolverContactConstraintPool[siData.m_orderTmpConstraintPool[j]];
+				btScalar residual = siData.m_resolveSingleConstraintRowLowerLimit(siData.m_tmpSolverBodyPool[solveManifold.m_solverBodyIdA], siData.m_tmpSolverBodyPool[solveManifold.m_solverBodyIdB], solveManifold);
 				leastSquaresResidual = btMax(leastSquaresResidual, residual * residual);
 			}
 
 			///solve all friction constraints
 
-			int numFrictionPoolConstraints = m_tmpSolverContactFrictionConstraintPool.size();
+			int numFrictionPoolConstraints = siData.m_tmpSolverContactFrictionConstraintPool.size();
 			for (j = 0; j < numFrictionPoolConstraints; j++)
 			{
-				btSolverConstraint& solveManifold = m_tmpSolverContactFrictionConstraintPool[m_orderFrictionConstraintPool[j]];
-				btScalar totalImpulse = m_tmpSolverContactConstraintPool[solveManifold.m_frictionIndex].m_appliedImpulse;
+				btSolverConstraint& solveManifold = siData.m_tmpSolverContactFrictionConstraintPool[siData.m_orderFrictionConstraintPool[j]];
+				btScalar totalImpulse = siData.m_tmpSolverContactConstraintPool[solveManifold.m_frictionIndex].m_appliedImpulse;
 
 				if (totalImpulse > btScalar(0))
 				{
 					solveManifold.m_lowerLimit = -(solveManifold.m_friction * totalImpulse);
 					solveManifold.m_upperLimit = solveManifold.m_friction * totalImpulse;
 
-					btScalar residual = resolveSingleConstraintRowGeneric(m_tmpSolverBodyPool[solveManifold.m_solverBodyIdA], m_tmpSolverBodyPool[solveManifold.m_solverBodyIdB], solveManifold);
+					btScalar residual = siData.m_resolveSingleConstraintRowGeneric(siData.m_tmpSolverBodyPool[solveManifold.m_solverBodyIdA], siData.m_tmpSolverBodyPool[solveManifold.m_solverBodyIdB], solveManifold);
 					leastSquaresResidual = btMax(leastSquaresResidual, residual * residual);
 				}
 			}
 		}
 
-		int numRollingFrictionPoolConstraints = m_tmpSolverContactRollingFrictionConstraintPool.size();
+		int numRollingFrictionPoolConstraints = siData.m_tmpSolverContactRollingFrictionConstraintPool.size();
 		for (int j = 0; j < numRollingFrictionPoolConstraints; j++)
 		{
-			btSolverConstraint& rollingFrictionConstraint = m_tmpSolverContactRollingFrictionConstraintPool[j];
-			btScalar totalImpulse = m_tmpSolverContactConstraintPool[rollingFrictionConstraint.m_frictionIndex].m_appliedImpulse;
+			btSolverConstraint& rollingFrictionConstraint = siData.m_tmpSolverContactRollingFrictionConstraintPool[j];
+			btScalar totalImpulse = siData.m_tmpSolverContactConstraintPool[rollingFrictionConstraint.m_frictionIndex].m_appliedImpulse;
 			if (totalImpulse > btScalar(0))
 			{
 				btScalar rollingFrictionMagnitude = rollingFrictionConstraint.m_friction * totalImpulse;
@@ -1708,7 +2130,7 @@ btScalar btSequentialImpulseConstraintSolver::solveSingleIteration(int iteration
 				rollingFrictionConstraint.m_lowerLimit = -rollingFrictionMagnitude;
 				rollingFrictionConstraint.m_upperLimit = rollingFrictionMagnitude;
 
-				btScalar residual = resolveSingleConstraintRowGeneric(m_tmpSolverBodyPool[rollingFrictionConstraint.m_solverBodyIdA], m_tmpSolverBodyPool[rollingFrictionConstraint.m_solverBodyIdB], rollingFrictionConstraint);
+				btScalar residual = siData.m_resolveSingleConstraintRowGeneric(siData.m_tmpSolverBodyPool[rollingFrictionConstraint.m_solverBodyIdA], siData.m_tmpSolverBodyPool[rollingFrictionConstraint.m_solverBodyIdB], rollingFrictionConstraint);
 				leastSquaresResidual = btMax(leastSquaresResidual, residual * residual);
 			}
 		}
@@ -1716,8 +2138,56 @@ btScalar btSequentialImpulseConstraintSolver::solveSingleIteration(int iteration
 	return leastSquaresResidual;
 }
 
+
+btScalar btSequentialImpulseConstraintSolver::solveSingleIteration(int iteration, btCollisionObject** /*bodies */, int /*numBodies*/, btPersistentManifold** /*manifoldPtr*/, int /*numManifolds*/, btTypedConstraint** constraints, int numConstraints, const btContactSolverInfo& infoGlobal, btIDebugDraw* /*debugDrawer*/)
+{
+	btSISolverSingleIterationData siData(m_tmpSolverBodyPool,
+		m_tmpSolverContactConstraintPool,
+		m_tmpSolverNonContactConstraintPool,
+		m_tmpSolverContactFrictionConstraintPool,
+		m_tmpSolverContactRollingFrictionConstraintPool,
+		m_orderTmpConstraintPool,
+		m_orderNonContactConstraintPool,
+		m_orderFrictionConstraintPool,
+		m_tmpConstraintSizesPool,
+		m_resolveSingleConstraintRowGeneric,
+		m_resolveSingleConstraintRowLowerLimit,
+		m_resolveSplitPenetrationImpulse,
+		m_kinematicBodyUniqueIdToSolverBodyTable,
+		m_btSeed2,
+		m_fixedBodyId,
+		m_maxOverrideNumSolverIterations);
+
+	btScalar leastSquaresResidual = btSequentialImpulseConstraintSolver::solveSingleIterationInternal(siData,
+		iteration, constraints, numConstraints, infoGlobal);
+	return leastSquaresResidual;
+}
+
 void btSequentialImpulseConstraintSolver::solveGroupCacheFriendlySplitImpulseIterations(btCollisionObject** bodies, int numBodies, btPersistentManifold** manifoldPtr, int numManifolds, btTypedConstraint** constraints, int numConstraints, const btContactSolverInfo& infoGlobal, btIDebugDraw* debugDrawer)
 {
+	btSISolverSingleIterationData siData(m_tmpSolverBodyPool,
+		m_tmpSolverContactConstraintPool,
+		m_tmpSolverNonContactConstraintPool,
+		m_tmpSolverContactFrictionConstraintPool,
+		m_tmpSolverContactRollingFrictionConstraintPool,
+		m_orderTmpConstraintPool,
+		m_orderNonContactConstraintPool,
+		m_orderFrictionConstraintPool,
+		m_tmpConstraintSizesPool,
+		m_resolveSingleConstraintRowGeneric,
+		m_resolveSingleConstraintRowLowerLimit,
+		m_resolveSplitPenetrationImpulse,
+		m_kinematicBodyUniqueIdToSolverBodyTable,
+		m_btSeed2,
+		m_fixedBodyId,
+		m_maxOverrideNumSolverIterations);
+
+	solveGroupCacheFriendlySplitImpulseIterationsInternal(siData,
+		bodies, numBodies, manifoldPtr, numManifolds, constraints, numConstraints, infoGlobal, debugDrawer);
+
+}
+void btSequentialImpulseConstraintSolver::solveGroupCacheFriendlySplitImpulseIterationsInternal(btSISolverSingleIterationData& siData, btCollisionObject** bodies, int numBodies, btPersistentManifold** manifoldPtr, int numManifolds, btTypedConstraint** constraints, int numConstraints, const btContactSolverInfo& infoGlobal, btIDebugDraw* debugDrawer)
+{
 	BT_PROFILE("solveGroupCacheFriendlySplitImpulseIterations");
 	int iteration;
 	if (infoGlobal.m_splitImpulse)
@@ -1727,13 +2197,13 @@ void btSequentialImpulseConstraintSolver::solveGroupCacheFriendlySplitImpulseIte
 			{
 				btScalar leastSquaresResidual = 0.f;
 				{
-					int numPoolConstraints = m_tmpSolverContactConstraintPool.size();
+					int numPoolConstraints = siData.m_tmpSolverContactConstraintPool.size();
 					int j;
 					for (j = 0; j < numPoolConstraints; j++)
 					{
-						const btSolverConstraint& solveManifold = m_tmpSolverContactConstraintPool[m_orderTmpConstraintPool[j]];
+						const btSolverConstraint& solveManifold = siData.m_tmpSolverContactConstraintPool[siData.m_orderTmpConstraintPool[j]];
 
-						btScalar residual = resolveSplitPenetrationImpulse(m_tmpSolverBodyPool[solveManifold.m_solverBodyIdA], m_tmpSolverBodyPool[solveManifold.m_solverBodyIdB], solveManifold);
+						btScalar residual = siData.m_resolveSplitPenetrationImpulse(siData.m_tmpSolverBodyPool[solveManifold.m_solverBodyIdA], siData.m_tmpSolverBodyPool[solveManifold.m_solverBodyIdB], solveManifold);
 						leastSquaresResidual = btMax(leastSquaresResidual, residual * residual);
 					}
 				}
@@ -1760,7 +2230,7 @@ btScalar btSequentialImpulseConstraintSolver::solveGroupCacheFriendlyIterations(
 		int maxIterations = m_maxOverrideNumSolverIterations > infoGlobal.m_numIterations ? m_maxOverrideNumSolverIterations : infoGlobal.m_numIterations;
 
 		for (int iteration = 0; iteration < maxIterations; iteration++)
-		//for ( int iteration = maxIterations-1  ; iteration >= 0;iteration--)
+			//for ( int iteration = maxIterations-1  ; iteration >= 0;iteration--)
 		{
 			m_leastSquaresResidual = solveSingleIteration(iteration, bodies, numBodies, manifoldPtr, numManifolds, constraints, numConstraints, infoGlobal, debugDrawer);
 
@@ -1769,6 +2239,14 @@ btScalar btSequentialImpulseConstraintSolver::solveGroupCacheFriendlyIterations(
 #ifdef VERBOSE_RESIDUAL_PRINTF
 				printf("residual = %f at iteration #%d\n", m_leastSquaresResidual, iteration);
 #endif
+				m_analyticsData.m_numSolverCalls++;
+				m_analyticsData.m_numIterationsUsed = iteration+1;
+				m_analyticsData.m_islandId = -2;
+				if (numBodies>0)
+					m_analyticsData.m_islandId = bodies[0]->getCompanionId();
+				m_analyticsData.m_numBodies = numBodies;
+				m_analyticsData.m_numContactManifolds = numManifolds;
+				m_analyticsData.m_remainingLeastSquaresResidual = m_leastSquaresResidual;
 				break;
 			}
 		}
@@ -1776,31 +2254,42 @@ btScalar btSequentialImpulseConstraintSolver::solveGroupCacheFriendlyIterations(
 	return 0.f;
 }
 
-void btSequentialImpulseConstraintSolver::writeBackContacts(int iBegin, int iEnd, const btContactSolverInfo& infoGlobal)
+void btSequentialImpulseConstraintSolver::writeBackContactsInternal(btConstraintArray& tmpSolverContactConstraintPool, btConstraintArray& tmpSolverContactFrictionConstraintPool, int iBegin, int iEnd, const btContactSolverInfo& infoGlobal)
 {
 	for (int j = iBegin; j < iEnd; j++)
 	{
-		const btSolverConstraint& solveManifold = m_tmpSolverContactConstraintPool[j];
+		const btSolverConstraint& solveManifold = tmpSolverContactConstraintPool[j];
 		btManifoldPoint* pt = (btManifoldPoint*)solveManifold.m_originalContactPoint;
 		btAssert(pt);
 		pt->m_appliedImpulse = solveManifold.m_appliedImpulse;
 		//	float f = m_tmpSolverContactFrictionConstraintPool[solveManifold.m_frictionIndex].m_appliedImpulse;
 		//	printf("pt->m_appliedImpulseLateral1 = %f\n", f);
-		pt->m_appliedImpulseLateral1 = m_tmpSolverContactFrictionConstraintPool[solveManifold.m_frictionIndex].m_appliedImpulse;
+		pt->m_appliedImpulseLateral1 = tmpSolverContactFrictionConstraintPool[solveManifold.m_frictionIndex].m_appliedImpulse;
 		//printf("pt->m_appliedImpulseLateral1 = %f\n", pt->m_appliedImpulseLateral1);
 		if ((infoGlobal.m_solverMode & SOLVER_USE_2_FRICTION_DIRECTIONS))
 		{
-			pt->m_appliedImpulseLateral2 = m_tmpSolverContactFrictionConstraintPool[solveManifold.m_frictionIndex + 1].m_appliedImpulse;
+			pt->m_appliedImpulseLateral2 = tmpSolverContactFrictionConstraintPool[solveManifold.m_frictionIndex + 1].m_appliedImpulse;
 		}
 		//do a callback here?
 	}
 }
 
+void btSequentialImpulseConstraintSolver::writeBackContacts(int iBegin, int iEnd, const btContactSolverInfo& infoGlobal)
+{
+	writeBackContactsInternal(m_tmpSolverContactConstraintPool, m_tmpSolverContactFrictionConstraintPool, iBegin, iEnd, infoGlobal);
+
+}
+
 void btSequentialImpulseConstraintSolver::writeBackJoints(int iBegin, int iEnd, const btContactSolverInfo& infoGlobal)
 {
+	writeBackJointsInternal(m_tmpSolverNonContactConstraintPool, iBegin, iEnd, infoGlobal);
+}
+
+void btSequentialImpulseConstraintSolver::writeBackJointsInternal(btConstraintArray& tmpSolverNonContactConstraintPool, int iBegin, int iEnd, const btContactSolverInfo& infoGlobal)
+{
 	for (int j = iBegin; j < iEnd; j++)
 	{
-		const btSolverConstraint& solverConstr = m_tmpSolverNonContactConstraintPool[j];
+		const btSolverConstraint& solverConstr = tmpSolverNonContactConstraintPool[j];
 		btTypedConstraint* constr = (btTypedConstraint*)solverConstr.m_originalContactPoint;
 		btJointFeedback* fb = constr->getJointFeedback();
 		if (fb)
@@ -1821,53 +2310,79 @@ void btSequentialImpulseConstraintSolver::writeBackJoints(int iBegin, int iEnd,
 
 void btSequentialImpulseConstraintSolver::writeBackBodies(int iBegin, int iEnd, const btContactSolverInfo& infoGlobal)
 {
+	writeBackBodiesInternal(m_tmpSolverBodyPool, iBegin, iEnd, infoGlobal);
+}
+void btSequentialImpulseConstraintSolver::writeBackBodiesInternal(btAlignedObjectArray<btSolverBody>& tmpSolverBodyPool, int iBegin, int iEnd, const btContactSolverInfo& infoGlobal)
+{
 	for (int i = iBegin; i < iEnd; i++)
 	{
-		btRigidBody* body = m_tmpSolverBodyPool[i].m_originalBody;
+		btRigidBody* body = tmpSolverBodyPool[i].m_originalBody;
 		if (body)
 		{
 			if (infoGlobal.m_splitImpulse)
-				m_tmpSolverBodyPool[i].writebackVelocityAndTransform(infoGlobal.m_timeStep, infoGlobal.m_splitImpulseTurnErp);
+				tmpSolverBodyPool[i].writebackVelocityAndTransform(infoGlobal.m_timeStep, infoGlobal.m_splitImpulseTurnErp);
 			else
-				m_tmpSolverBodyPool[i].writebackVelocity();
+				tmpSolverBodyPool[i].writebackVelocity();
 
-			m_tmpSolverBodyPool[i].m_originalBody->setLinearVelocity(
-				m_tmpSolverBodyPool[i].m_linearVelocity +
-				m_tmpSolverBodyPool[i].m_externalForceImpulse);
+			tmpSolverBodyPool[i].m_originalBody->setLinearVelocity(
+				tmpSolverBodyPool[i].m_linearVelocity +
+				tmpSolverBodyPool[i].m_externalForceImpulse);
 
-			m_tmpSolverBodyPool[i].m_originalBody->setAngularVelocity(
-				m_tmpSolverBodyPool[i].m_angularVelocity +
-				m_tmpSolverBodyPool[i].m_externalTorqueImpulse);
+			tmpSolverBodyPool[i].m_originalBody->setAngularVelocity(
+				tmpSolverBodyPool[i].m_angularVelocity +
+				tmpSolverBodyPool[i].m_externalTorqueImpulse);
 
 			if (infoGlobal.m_splitImpulse)
-				m_tmpSolverBodyPool[i].m_originalBody->setWorldTransform(m_tmpSolverBodyPool[i].m_worldTransform);
+				tmpSolverBodyPool[i].m_originalBody->setWorldTransform(tmpSolverBodyPool[i].m_worldTransform);
 
-			m_tmpSolverBodyPool[i].m_originalBody->setCompanionId(-1);
+			tmpSolverBodyPool[i].m_originalBody->setCompanionId(-1);
 		}
 	}
 }
 
-btScalar btSequentialImpulseConstraintSolver::solveGroupCacheFriendlyFinish(btCollisionObject** bodies, int numBodies, const btContactSolverInfo& infoGlobal)
+btScalar btSequentialImpulseConstraintSolver::solveGroupCacheFriendlyFinishInternal(btSISolverSingleIterationData& siData, btCollisionObject** bodies, int numBodies, const btContactSolverInfo& infoGlobal)
 {
 	BT_PROFILE("solveGroupCacheFriendlyFinish");
 
 	if (infoGlobal.m_solverMode & SOLVER_USE_WARMSTARTING)
 	{
-		writeBackContacts(0, m_tmpSolverContactConstraintPool.size(), infoGlobal);
+		writeBackContactsInternal(siData.m_tmpSolverContactConstraintPool, siData.m_tmpSolverContactFrictionConstraintPool, 0, siData.m_tmpSolverContactConstraintPool.size(), infoGlobal);
 	}
 
-	writeBackJoints(0, m_tmpSolverNonContactConstraintPool.size(), infoGlobal);
-	writeBackBodies(0, m_tmpSolverBodyPool.size(), infoGlobal);
+	writeBackJointsInternal(siData.m_tmpSolverNonContactConstraintPool, 0, siData.m_tmpSolverNonContactConstraintPool.size(), infoGlobal);
+	writeBackBodiesInternal(siData.m_tmpSolverBodyPool, 0, siData.m_tmpSolverBodyPool.size(), infoGlobal);
 
-	m_tmpSolverContactConstraintPool.resizeNoInitialize(0);
-	m_tmpSolverNonContactConstraintPool.resizeNoInitialize(0);
-	m_tmpSolverContactFrictionConstraintPool.resizeNoInitialize(0);
-	m_tmpSolverContactRollingFrictionConstraintPool.resizeNoInitialize(0);
+	siData.m_tmpSolverContactConstraintPool.resizeNoInitialize(0);
+	siData.m_tmpSolverNonContactConstraintPool.resizeNoInitialize(0);
+	siData.m_tmpSolverContactFrictionConstraintPool.resizeNoInitialize(0);
+	siData.m_tmpSolverContactRollingFrictionConstraintPool.resizeNoInitialize(0);
 
-	m_tmpSolverBodyPool.resizeNoInitialize(0);
+	siData.m_tmpSolverBodyPool.resizeNoInitialize(0);
 	return 0.f;
 }
 
+btScalar btSequentialImpulseConstraintSolver::solveGroupCacheFriendlyFinish(btCollisionObject** bodies, int numBodies, const btContactSolverInfo& infoGlobal)
+{
+	btSISolverSingleIterationData siData(m_tmpSolverBodyPool,
+		m_tmpSolverContactConstraintPool,
+		m_tmpSolverNonContactConstraintPool,
+		m_tmpSolverContactFrictionConstraintPool,
+		m_tmpSolverContactRollingFrictionConstraintPool,
+		m_orderTmpConstraintPool,
+		m_orderNonContactConstraintPool,
+		m_orderFrictionConstraintPool,
+		m_tmpConstraintSizesPool,
+		m_resolveSingleConstraintRowGeneric,
+		m_resolveSingleConstraintRowLowerLimit,
+		m_resolveSplitPenetrationImpulse,
+		m_kinematicBodyUniqueIdToSolverBodyTable,
+		m_btSeed2,
+		m_fixedBodyId,
+		m_maxOverrideNumSolverIterations);
+
+	return btSequentialImpulseConstraintSolver::solveGroupCacheFriendlyFinishInternal(siData, bodies, numBodies, infoGlobal);
+}
+
 /// btSequentialImpulseConstraintSolver Sequentially applies impulses
 btScalar btSequentialImpulseConstraintSolver::solveGroup(btCollisionObject** bodies, int numBodies, btPersistentManifold** manifoldPtr, int numManifolds, btTypedConstraint** constraints, int numConstraints, const btContactSolverInfo& infoGlobal, btIDebugDraw* debugDrawer, btDispatcher* /*dispatcher*/)
 {
@@ -1886,4 +2401,4 @@ btScalar btSequentialImpulseConstraintSolver::solveGroup(btCollisionObject** bod
 void btSequentialImpulseConstraintSolver::reset()
 {
 	m_btSeed2 = 0;
-}
+}
\ No newline at end of file
diff --git a/thirdparty/bullet/BulletDynamics/ConstraintSolver/btSequentialImpulseConstraintSolver.h b/thirdparty/bullet/BulletDynamics/ConstraintSolver/btSequentialImpulseConstraintSolver.h
index 70db83b063..2b88e25be7 100644
--- a/thirdparty/bullet/BulletDynamics/ConstraintSolver/btSequentialImpulseConstraintSolver.h
+++ b/thirdparty/bullet/BulletDynamics/ConstraintSolver/btSequentialImpulseConstraintSolver.h
@@ -29,10 +29,91 @@ class btCollisionObject;
 
 typedef btScalar (*btSingleConstraintRowSolver)(btSolverBody&, btSolverBody&, const btSolverConstraint&);
 
+struct btSISolverSingleIterationData
+{
+	btAlignedObjectArray<btSolverBody>& m_tmpSolverBodyPool;
+	btConstraintArray& m_tmpSolverContactConstraintPool;
+	btConstraintArray& m_tmpSolverNonContactConstraintPool;
+	btConstraintArray& m_tmpSolverContactFrictionConstraintPool;
+	btConstraintArray& m_tmpSolverContactRollingFrictionConstraintPool;
+
+	btAlignedObjectArray<int>& m_orderTmpConstraintPool;
+	btAlignedObjectArray<int>& m_orderNonContactConstraintPool;
+	btAlignedObjectArray<int>& m_orderFrictionConstraintPool;
+	btAlignedObjectArray<btTypedConstraint::btConstraintInfo1>& m_tmpConstraintSizesPool;
+	unsigned long& m_seed;
+
+	btSingleConstraintRowSolver& m_resolveSingleConstraintRowGeneric;
+	btSingleConstraintRowSolver& m_resolveSingleConstraintRowLowerLimit;
+	btSingleConstraintRowSolver& m_resolveSplitPenetrationImpulse;
+	btAlignedObjectArray<int>& m_kinematicBodyUniqueIdToSolverBodyTable;
+	int& m_fixedBodyId;
+	int& m_maxOverrideNumSolverIterations;
+	int getOrInitSolverBody(btCollisionObject & body, btScalar timeStep);
+	static void initSolverBody(btSolverBody * solverBody, btCollisionObject * collisionObject, btScalar timeStep);
+	int getSolverBody(btCollisionObject& body) const;
+
+
+	btSISolverSingleIterationData(btAlignedObjectArray<btSolverBody>& tmpSolverBodyPool,
+		btConstraintArray& tmpSolverContactConstraintPool,
+		btConstraintArray& tmpSolverNonContactConstraintPool,
+		btConstraintArray& tmpSolverContactFrictionConstraintPool,
+		btConstraintArray& tmpSolverContactRollingFrictionConstraintPool,
+		btAlignedObjectArray<int>& orderTmpConstraintPool,
+		btAlignedObjectArray<int>& orderNonContactConstraintPool,
+		btAlignedObjectArray<int>& orderFrictionConstraintPool,
+		btAlignedObjectArray<btTypedConstraint::btConstraintInfo1>& tmpConstraintSizesPool,
+		btSingleConstraintRowSolver& resolveSingleConstraintRowGeneric,
+		btSingleConstraintRowSolver& resolveSingleConstraintRowLowerLimit,
+		btSingleConstraintRowSolver& resolveSplitPenetrationImpulse,
+		btAlignedObjectArray<int>& kinematicBodyUniqueIdToSolverBodyTable,
+		unsigned long& seed,
+		int& fixedBodyId,
+		int& maxOverrideNumSolverIterations
+	)
+		:m_tmpSolverBodyPool(tmpSolverBodyPool),
+		m_tmpSolverContactConstraintPool(tmpSolverContactConstraintPool),
+		m_tmpSolverNonContactConstraintPool(tmpSolverNonContactConstraintPool),
+		m_tmpSolverContactFrictionConstraintPool(tmpSolverContactFrictionConstraintPool),
+		m_tmpSolverContactRollingFrictionConstraintPool(tmpSolverContactRollingFrictionConstraintPool),
+		m_orderTmpConstraintPool(orderTmpConstraintPool),
+		m_orderNonContactConstraintPool(orderNonContactConstraintPool),
+		m_orderFrictionConstraintPool(orderFrictionConstraintPool),
+		m_tmpConstraintSizesPool(tmpConstraintSizesPool),
+		m_seed(seed),
+		m_resolveSingleConstraintRowGeneric(resolveSingleConstraintRowGeneric),
+		m_resolveSingleConstraintRowLowerLimit(resolveSingleConstraintRowLowerLimit),
+		m_resolveSplitPenetrationImpulse(resolveSplitPenetrationImpulse),
+		m_kinematicBodyUniqueIdToSolverBodyTable(kinematicBodyUniqueIdToSolverBodyTable),
+		m_fixedBodyId(fixedBodyId),
+		m_maxOverrideNumSolverIterations(maxOverrideNumSolverIterations)
+	{
+	}
+};
+
+struct btSolverAnalyticsData
+{
+	btSolverAnalyticsData()
+	{
+		m_numSolverCalls = 0;
+		m_numIterationsUsed = -1;
+		m_remainingLeastSquaresResidual = -1;
+		m_islandId = -2;
+	}
+	int m_islandId;
+	int m_numBodies;
+	int m_numContactManifolds;
+	int m_numSolverCalls;
+	int m_numIterationsUsed;
+	double m_remainingLeastSquaresResidual;
+};
+
 ///The btSequentialImpulseConstraintSolver is a fast SIMD implementation of the Projected Gauss Seidel (iterative LCP) method.
 ATTRIBUTE_ALIGNED16(class)
 btSequentialImpulseConstraintSolver : public btConstraintSolver
 {
+	
+
 protected:
 	btAlignedObjectArray<btSolverBody> m_tmpSolverBodyPool;
 	btConstraintArray m_tmpSolverContactConstraintPool;
@@ -64,26 +145,26 @@ protected:
 	btScalar m_leastSquaresResidual;
 
 	void setupFrictionConstraint(btSolverConstraint & solverConstraint, const btVector3& normalAxis, int solverBodyIdA, int solverBodyIdB,
-								 btManifoldPoint& cp, const btVector3& rel_pos1, const btVector3& rel_pos2,
-								 btCollisionObject* colObj0, btCollisionObject* colObj1, btScalar relaxation,
-								 const btContactSolverInfo& infoGlobal,
-								 btScalar desiredVelocity = 0., btScalar cfmSlip = 0.);
+		btManifoldPoint& cp, const btVector3& rel_pos1, const btVector3& rel_pos2,
+		btCollisionObject* colObj0, btCollisionObject* colObj1, btScalar relaxation,
+		const btContactSolverInfo& infoGlobal,
+		btScalar desiredVelocity = 0., btScalar cfmSlip = 0.);
 
 	void setupTorsionalFrictionConstraint(btSolverConstraint & solverConstraint, const btVector3& normalAxis, int solverBodyIdA, int solverBodyIdB,
-										  btManifoldPoint& cp, btScalar combinedTorsionalFriction, const btVector3& rel_pos1, const btVector3& rel_pos2,
-										  btCollisionObject* colObj0, btCollisionObject* colObj1, btScalar relaxation,
-										  btScalar desiredVelocity = 0., btScalar cfmSlip = 0.);
+		btManifoldPoint& cp, btScalar combinedTorsionalFriction, const btVector3& rel_pos1, const btVector3& rel_pos2,
+		btCollisionObject* colObj0, btCollisionObject* colObj1, btScalar relaxation,
+		btScalar desiredVelocity = 0., btScalar cfmSlip = 0.);
 
 	btSolverConstraint& addFrictionConstraint(const btVector3& normalAxis, int solverBodyIdA, int solverBodyIdB, int frictionIndex, btManifoldPoint& cp, const btVector3& rel_pos1, const btVector3& rel_pos2, btCollisionObject* colObj0, btCollisionObject* colObj1, btScalar relaxation, const btContactSolverInfo& infoGlobal, btScalar desiredVelocity = 0., btScalar cfmSlip = 0.);
 	btSolverConstraint& addTorsionalFrictionConstraint(const btVector3& normalAxis, int solverBodyIdA, int solverBodyIdB, int frictionIndex, btManifoldPoint& cp, btScalar torsionalFriction, const btVector3& rel_pos1, const btVector3& rel_pos2, btCollisionObject* colObj0, btCollisionObject* colObj1, btScalar relaxation, btScalar desiredVelocity = 0, btScalar cfmSlip = 0.f);
 
 	void setupContactConstraint(btSolverConstraint & solverConstraint, int solverBodyIdA, int solverBodyIdB, btManifoldPoint& cp,
-								const btContactSolverInfo& infoGlobal, btScalar& relaxation, const btVector3& rel_pos1, const btVector3& rel_pos2);
+		const btContactSolverInfo& infoGlobal, btScalar& relaxation, const btVector3& rel_pos1, const btVector3& rel_pos2);
 
 	static void applyAnisotropicFriction(btCollisionObject * colObj, btVector3 & frictionDirection, int frictionMode);
 
 	void setFrictionConstraintImpulse(btSolverConstraint & solverConstraint, int solverBodyIdA, int solverBodyIdB,
-									  btManifoldPoint& cp, const btContactSolverInfo& infoGlobal);
+		btManifoldPoint& cp, const btContactSolverInfo& infoGlobal);
 
 	///m_btSeed2 is used for re-arranging the constraint rows. improves convergence/quality of friction
 	unsigned long m_btSeed2;
@@ -97,6 +178,7 @@ protected:
 	virtual void convertJoints(btTypedConstraint * *constraints, int numConstraints, const btContactSolverInfo& infoGlobal);
 	void convertJoint(btSolverConstraint * currentConstraintRow, btTypedConstraint * constraint, const btTypedConstraint::btConstraintInfo1& info1, int solverBodyIdA, int solverBodyIdB, const btContactSolverInfo& infoGlobal);
 
+
 	virtual void convertBodies(btCollisionObject * *bodies, int numBodies, const btContactSolverInfo& infoGlobal);
 
 	btScalar resolveSplitPenetrationSIMD(btSolverBody & bodyA, btSolverBody & bodyB, const btSolverConstraint& contactConstraint)
@@ -122,7 +204,8 @@ protected:
 		return m_resolveSplitPenetrationImpulse(bodyA, bodyB, contactConstraint);
 	}
 
-protected:
+public:
+
 	void writeBackContacts(int iBegin, int iEnd, const btContactSolverInfo& infoGlobal);
 	void writeBackJoints(int iBegin, int iEnd, const btContactSolverInfo& infoGlobal);
 	void writeBackBodies(int iBegin, int iEnd, const btContactSolverInfo& infoGlobal);
@@ -130,6 +213,7 @@ protected:
 	virtual btScalar solveGroupCacheFriendlyFinish(btCollisionObject * *bodies, int numBodies, const btContactSolverInfo& infoGlobal);
 	virtual btScalar solveSingleIteration(int iteration, btCollisionObject** bodies, int numBodies, btPersistentManifold** manifoldPtr, int numManifolds, btTypedConstraint** constraints, int numConstraints, const btContactSolverInfo& infoGlobal, btIDebugDraw* debugDrawer);
 
+
 	virtual btScalar solveGroupCacheFriendlySetup(btCollisionObject * *bodies, int numBodies, btPersistentManifold** manifoldPtr, int numManifolds, btTypedConstraint** constraints, int numConstraints, const btContactSolverInfo& infoGlobal, btIDebugDraw* debugDrawer);
 	virtual btScalar solveGroupCacheFriendlyIterations(btCollisionObject * *bodies, int numBodies, btPersistentManifold** manifoldPtr, int numManifolds, btTypedConstraint** constraints, int numConstraints, const btContactSolverInfo& infoGlobal, btIDebugDraw* debugDrawer);
 
@@ -141,13 +225,52 @@ public:
 
 	virtual btScalar solveGroup(btCollisionObject * *bodies, int numBodies, btPersistentManifold** manifold, int numManifolds, btTypedConstraint** constraints, int numConstraints, const btContactSolverInfo& info, btIDebugDraw* debugDrawer, btDispatcher* dispatcher);
 
+	static btScalar solveSingleIterationInternal(btSISolverSingleIterationData& siData, int iteration, btTypedConstraint** constraints, int numConstraints, const btContactSolverInfo& infoGlobal);
+	static void convertBodiesInternal(btSISolverSingleIterationData& siData, btCollisionObject** bodies, int numBodies, const btContactSolverInfo& infoGlobal);
+	static void convertJointsInternal(btSISolverSingleIterationData& siData, btTypedConstraint** constraints, int numConstraints, const btContactSolverInfo& infoGlobal);
+	static void convertContactInternal(btSISolverSingleIterationData& siData, btPersistentManifold * manifold, const btContactSolverInfo& infoGlobal);
+	static void setupContactConstraintInternal(btSISolverSingleIterationData& siData, btSolverConstraint& solverConstraint, int solverBodyIdA, int solverBodyIdB, btManifoldPoint& cp, const btContactSolverInfo& infoGlobal, btScalar& relaxation,
+		const btVector3& rel_pos1, const btVector3& rel_pos2);
+	static btScalar restitutionCurveInternal(btScalar rel_vel, btScalar restitution, btScalar velocityThreshold);
+	static btSolverConstraint& addTorsionalFrictionConstraintInternal(btAlignedObjectArray<btSolverBody>& tmpSolverBodyPool, btConstraintArray& tmpSolverContactRollingFrictionConstraintPool, const btVector3& normalAxis, int solverBodyIdA, int solverBodyIdB, int frictionIndex, btManifoldPoint& cp, btScalar combinedTorsionalFriction, const btVector3& rel_pos1, const btVector3& rel_pos2, btCollisionObject* colObj0, btCollisionObject* colObj1, btScalar relaxation, btScalar desiredVelocity = 0, btScalar cfmSlip = 0.);
+	static void setupTorsionalFrictionConstraintInternal(btAlignedObjectArray<btSolverBody>& tmpSolverBodyPool, btSolverConstraint& solverConstraint, const btVector3& normalAxis1, int solverBodyIdA, int solverBodyIdB,
+		btManifoldPoint& cp, btScalar combinedTorsionalFriction, const btVector3& rel_pos1, const btVector3& rel_pos2,
+		btCollisionObject* colObj0, btCollisionObject* colObj1, btScalar relaxation,
+		btScalar desiredVelocity, btScalar cfmSlip);
+	static void setupFrictionConstraintInternal(btAlignedObjectArray<btSolverBody>& tmpSolverBodyPool, btSolverConstraint& solverConstraint, const btVector3& normalAxis, int solverBodyIdA, int solverBodyIdB, btManifoldPoint& cp, const btVector3& rel_pos1, const btVector3& rel_pos2, btCollisionObject* colObj0, btCollisionObject* colObj1, btScalar relaxation, const btContactSolverInfo& infoGlobal, btScalar desiredVelocity, btScalar cfmSlip);
+	static btSolverConstraint& addFrictionConstraintInternal(btAlignedObjectArray<btSolverBody>& tmpSolverBodyPool, btConstraintArray& tmpSolverContactFrictionConstraintPool, const btVector3& normalAxis, int solverBodyIdA, int solverBodyIdB, int frictionIndex, btManifoldPoint& cp, const btVector3& rel_pos1, const btVector3& rel_pos2, btCollisionObject* colObj0, btCollisionObject* colObj1, btScalar relaxation, const btContactSolverInfo& infoGlobal, btScalar desiredVelocity = 0., btScalar cfmSlip = 0.);
+	static void setFrictionConstraintImpulseInternal(btAlignedObjectArray<btSolverBody>& tmpSolverBodyPool, btConstraintArray& tmpSolverContactFrictionConstraintPool,
+
+		btSolverConstraint& solverConstraint,
+		int solverBodyIdA, int solverBodyIdB,
+		btManifoldPoint& cp, const btContactSolverInfo& infoGlobal);
+	static void convertJointInternal(btAlignedObjectArray<btSolverBody>& tmpSolverBodyPool,
+		int& maxOverrideNumSolverIterations,
+		btSolverConstraint* currentConstraintRow,
+		btTypedConstraint* constraint,
+		const btTypedConstraint::btConstraintInfo1& info1,
+		int solverBodyIdA,
+		int solverBodyIdB,
+		const btContactSolverInfo& infoGlobal);
+
+	static btScalar solveGroupCacheFriendlyFinishInternal(btSISolverSingleIterationData& siData, btCollisionObject** bodies, int numBodies, const btContactSolverInfo& infoGlobal);
+
+	static void writeBackContactsInternal(btConstraintArray& tmpSolverContactConstraintPool, btConstraintArray& tmpSolverContactFrictionConstraintPool, int iBegin, int iEnd, const btContactSolverInfo& infoGlobal);
+
+	static void writeBackJointsInternal(btConstraintArray& tmpSolverNonContactConstraintPool, int iBegin, int iEnd, const btContactSolverInfo& infoGlobal);
+	static void writeBackBodiesInternal(btAlignedObjectArray<btSolverBody>& tmpSolverBodyPool, int iBegin, int iEnd, const btContactSolverInfo& infoGlobal);
+	static void solveGroupCacheFriendlySplitImpulseIterationsInternal(btSISolverSingleIterationData& siData, btCollisionObject** bodies, int numBodies, btPersistentManifold** manifoldPtr, int numManifolds, btTypedConstraint** constraints, int numConstraints, const btContactSolverInfo& infoGlobal, btIDebugDraw* debugDrawer);
+
+
 	///clear internal cached data and reset random seed
 	virtual void reset();
 
 	unsigned long btRand2();
-
 	int btRandInt2(int n);
 
+	static unsigned long btRand2a(unsigned long& seed);
+	static int btRandInt2a(int n, unsigned long& seed);
+
 	void setRandSeed(unsigned long seed)
 	{
 		m_btSeed2 = seed;
@@ -179,15 +302,22 @@ public:
 		m_resolveSingleConstraintRowLowerLimit = rowSolver;
 	}
 
+
+
 	///Various implementations of solving a single constraint row using a generic equality constraint, using scalar reference, SSE2 or SSE4
-	btSingleConstraintRowSolver getScalarConstraintRowSolverGeneric();
-	btSingleConstraintRowSolver getSSE2ConstraintRowSolverGeneric();
-	btSingleConstraintRowSolver getSSE4_1ConstraintRowSolverGeneric();
+	static btSingleConstraintRowSolver getScalarConstraintRowSolverGeneric();
+	static btSingleConstraintRowSolver getSSE2ConstraintRowSolverGeneric();
+	static btSingleConstraintRowSolver getSSE4_1ConstraintRowSolverGeneric();
 
 	///Various implementations of solving a single constraint row using an inequality (lower limit) constraint, using scalar reference, SSE2 or SSE4
-	btSingleConstraintRowSolver getScalarConstraintRowSolverLowerLimit();
-	btSingleConstraintRowSolver getSSE2ConstraintRowSolverLowerLimit();
-	btSingleConstraintRowSolver getSSE4_1ConstraintRowSolverLowerLimit();
+	static btSingleConstraintRowSolver getScalarConstraintRowSolverLowerLimit();
+	static btSingleConstraintRowSolver getSSE2ConstraintRowSolverLowerLimit();
+	static btSingleConstraintRowSolver getSSE4_1ConstraintRowSolverLowerLimit();
+
+	static btSingleConstraintRowSolver getScalarSplitPenetrationImpulseGeneric();
+	static btSingleConstraintRowSolver getSSE2SplitPenetrationImpulseGeneric();
+
+	btSolverAnalyticsData m_analyticsData;
 };
 
 #endif  //BT_SEQUENTIAL_IMPULSE_CONSTRAINT_SOLVER_H