Added SSE4/FMA optimized constraint row solver implementation for btSequentialImpulseConstraintSolver,

thanks to Vladimir Bondarev (https://github.com/VladimirBondarev/bullet3/tree/c25d)

src/BulletDynamics/ConstraintSolver/btSequentialImpulseConstraintSolver.h

@@ -27,6 +27,8 @@ class btCollisionObject;
 #include "BulletCollision/NarrowPhaseCollision/btManifoldPoint.h"
 #include "BulletDynamics/ConstraintSolver/btConstraintSolver.h"
 
+typedef btSimdScalar(*btSingleConstraintRowSolver)(btSolverBody&, btSolverBody&, const btSolverConstraint&);
+
 ///The btSequentialImpulseConstraintSolver is a fast SIMD implementation of the Projected Gauss Seidel (iterative LCP) method.
 ATTRIBUTE_ALIGNED16(class) btSequentialImpulseConstraintSolver : public btConstraintSolver
 {
@@ -43,6 +45,10 @@ protected:
 	btAlignedObjectArray<btTypedConstraint::btConstraintInfo1> m_tmpConstraintSizesPool;
 	int							m_maxOverrideNumSolverIterations;
 	int m_fixedBodyId;
+
+	btSingleConstraintRowSolver m_resolveSingleConstraintRowGeneric;
+	btSingleConstraintRowSolver m_resolveSingleConstraintRowLowerLimit;
+
 	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, 
@@ -112,9 +118,7 @@ public:
 	virtual ~btSequentialImpulseConstraintSolver();
 
 	virtual btScalar solveGroup(btCollisionObject** bodies,int numBodies,btPersistentManifold** manifold,int numManifolds,btTypedConstraint** constraints,int numConstraints,const btContactSolverInfo& info, btIDebugDraw* debugDrawer,btDispatcher* dispatcher);
-	
-
-	
+		
 	///clear internal cached data and reset random seed
 	virtual	void	reset();
 	
@@ -136,6 +140,34 @@ public:
 	{
 		return BT_SEQUENTIAL_IMPULSE_SOLVER;
 	}
+
+	btSingleConstraintRowSolver	getActiveConstraintRowSolverGeneric()
+	{
+		return m_resolveSingleConstraintRowGeneric;
+	}
+	void setConstraintRowSolverGeneric(btSingleConstraintRowSolver rowSolver)
+	{
+		m_resolveSingleConstraintRowGeneric = rowSolver;
+	}
+	btSingleConstraintRowSolver	getActiveConstraintRowSolverLowerLimit()
+	{
+		return m_resolveSingleConstraintRowLowerLimit;
+	}
+	void setConstraintRowSolverLowerLimit(btSingleConstraintRowSolver rowSolver)
+	{
+		m_resolveSingleConstraintRowLowerLimit = rowSolver;
+	}
+
+
+	//	btSingleConstraintRowSolver	getScalarConstraintRowSolverLowerLimit();
+	btSingleConstraintRowSolver	getSSE2ConstraintRowSolverGeneric();
+	btSingleConstraintRowSolver	getSSE4_1ConstraintRowSolverGeneric();
+	btSingleConstraintRowSolver	getSSE2ConstraintRowSolverLowerLimit();
+	btSingleConstraintRowSolver	getSSE4_1ConstraintRowSolverLowerLimit();
+
+
+
+
 };