Added btNearCallback. This is similar to Open Dynamics Engine (ODE) dNearCallback, but important differences:

- contact points are persistent (lifetime more then one frame, for warmstarting/incremental contact point management)
- continuous collision detection, time of impact
Added btRigidBody::isInWorld(), returns true if btRigidBody is inside a btCollisionWorld/btDynamicsWorld derived class
Added angularFactor to btRigidbody, this helps some character control (no angular impulse applied)

src/BulletDynamics/Dynamics/btRigidBody.cpp

@@ -35,6 +35,7 @@ btRigidBody::btRigidBody(float mass, btMotionState* motionState, btCollisionShap
 	m_totalTorque(0.0f, 0.0f, 0.0f),
 	m_linearVelocity(0.0f, 0.0f, 0.0f),
 	m_angularVelocity(0.f,0.f,0.f),
+	m_angularFactor(1.f),
 	m_linearDamping(0.f),
 	m_angularDamping(0.5f),
 	m_optionalMotionState(motionState),

src/BulletDynamics/Dynamics/btRigidBody.h

@@ -47,6 +47,7 @@ class btRigidBody  : public btCollisionObject
 	btVector3		m_linearVelocity;
 	btVector3		m_angularVelocity;
 	btScalar		m_inverseMass;
+	btScalar		m_angularFactor;
 
 	btVector3		m_gravity;	
 	btVector3		m_invInertiaLocal;
@@ -159,7 +160,10 @@ public:
 		if (m_inverseMass != 0.f)
 		{
 			applyCentralImpulse(impulse);
-			applyTorqueImpulse(rel_pos.cross(impulse));
+			if (m_angularFactor)
+			{
+				applyTorqueImpulse(rel_pos.cross(impulse)*m_angularFactor);
+			}
 		}
 	}
 
@@ -169,7 +173,10 @@ public:
 		if (m_inverseMass != 0.f)
 		{
 			m_linearVelocity += linearComponent*impulseMagnitude;
-			m_angularVelocity += angularComponent*impulseMagnitude;
+			if (m_angularFactor)
+			{
+				m_angularVelocity += angularComponent*impulseMagnitude*m_angularFactor;
+			}
 		}
 	}
 	
@@ -321,7 +328,20 @@ public:
 	int	m_contactSolverType;
 	int	m_frictionSolverType;
 
-	
+	void	setAngularFactor(float angFac)
+	{
+		m_angularFactor = angFac;
+	}
+	float	getAngularFactor() const
+	{
+		return m_angularFactor;
+	}
+
+	//is this rigidbody added to a btCollisionWorld/btDynamicsWorld/btBroadphase?
+	bool	isInWorld() const
+	{
+		return (getBroadphaseProxy() != 0);
+	}
 
 	int	m_debugBodyId;
 };