///applyDamping damps the velocity, using the given m_linearDamping and m_angularDamping
void btRigidBody::applyDamping(btScalar timeStep)
{
//On new damping: see discussion/issue report here: http://code.google.com/p/bullet/issues/detail?id=74
//todo: do some performance comparisons (but other parts of the engine are probably bottleneck anyway
//#define USE_OLD_DAMPING_METHOD 1
#ifdef USE_OLD_DAMPING_METHOD
m_linearVelocity *= GEN_clamped((btScalar(1.) - timeStep * m_linearDamping), (btScalar)btScalar(0.0), (btScalar)btScalar(1.0));
m_angularVelocity *= GEN_clamped((btScalar(1.) - timeStep * m_angularDamping), (btScalar)btScalar(0.0), (btScalar)btScalar(1.0));
#else
m_linearVelocity *= btPow(btScalar(1)-m_linearDamping, timeStep);
m_angularVelocity *= btPow(btScalar(1)-m_angularDamping, timeStep);
#endif
if (m_additionalDamping)
{
//Additional damping can help avoiding lowpass jitter motion, help stability for ragdolls etc.
//Such damping is undesirable, so once the overall simulation quality of the rigid body dynamics system has improved, this should become obsolete
if ((m_angularVelocity.length2() < m_additionalAngularDampingThresholdSqr) &&
(m_linearVelocity.length2() < m_additionalLinearDampingThresholdSqr))
{
m_angularVelocity *= m_additionalDampingFactor;
m_linearVelocity *= m_additionalDampingFactor;
}
btScalar speed = m_linearVelocity.length();
if (speed < m_linearDamping)
{
btScalar dampVel = btScalar(0.005);
if (speed > dampVel)
{
btVector3 dir = m_linearVelocity.normalized();
m_linearVelocity -= dir * dampVel;
} else
{
m_linearVelocity.setValue(btScalar(0.),btScalar(0.),btScalar(0.));
}
}
btScalar angSpeed = m_angularVelocity.length();
if (angSpeed < m_angularDamping)
{
btScalar angDampVel = btScalar(0.005);
if (angSpeed > angDampVel)
{
btVector3 dir = m_angularVelocity.normalized();
m_angularVelocity -= dir * angDampVel;
} else
{
m_angularVelocity.setValue(btScalar(0.),btScalar(0.),btScalar(0.));
}
}
}
}
///applyDamping damps the velocity, using the given m_linearDamping and m_angularDamping
void btRigidBody::applyDamping(btScalar timeStep)
{
//m_linearVelocity *= GEN_clamped((btScalar(1.) - timeStep * m_linearDamping), (btScalar)btScalar(0.0), (btScalar)btScalar(1.0));
//m_angularVelocity *= GEN_clamped((btScalar(1.) - timeStep * m_angularDamping), (btScalar)btScalar(0.0), (btScalar)btScalar(1.0));
m_linearVelocity *= powf(GEN_clamped(1.0 - m_linearDamping, 0.0, 1.0),timeStep);
m_angularVelocity *= powf(GEN_clamped(1.0 - m_angularDamping, 0.0, 1.0),timeStep);
if (m_additionalDamping)
{
//Additional damping can help avoiding lowpass jitter motion, help stability for ragdolls etc.
//Such damping is undesirable, so once the overall simulation quality of the rigid body dynamics system has improved, this should become obsolete
if ((m_angularVelocity.length2() < m_additionalAngularDampingThresholdSqr) &&
(m_linearVelocity.length2() < m_additionalLinearDampingThresholdSqr))
{
m_angularVelocity *= m_additionalDampingFactor;
m_linearVelocity *= m_additionalDampingFactor;
}
btScalar speed = m_linearVelocity.length();
if (speed < m_linearDamping)
{
btScalar dampVel = btScalar(0.005);
if (speed > dampVel)
{
btVector3 dir = m_linearVelocity.normalized();
m_linearVelocity -= dir * dampVel;
} else
{
m_linearVelocity.setValue(btScalar(0.),btScalar(0.),btScalar(0.));
}
}
btScalar angSpeed = m_angularVelocity.length();
if (angSpeed < m_angularDamping)
{
btScalar angDampVel = btScalar(0.005);
if (angSpeed > angDampVel)
{
btVector3 dir = m_angularVelocity.normalized();
m_angularVelocity -= dir * angDampVel;
} else
{
m_angularVelocity.setValue(btScalar(0.),btScalar(0.),btScalar(0.));
}
}
}
}
void RigidBody::applyForces(SimdScalar step)
{
if (IsStatic())
return;
applyCentralForce(m_gravity);
m_linearVelocity *= GEN_clamped((1.f - step * gLinearAirDamping * m_linearDamping), 0.0f, 1.0f);
m_angularVelocity *= GEN_clamped((1.f - step * m_angularDamping), 0.0f, 1.0f);
#define FORCE_VELOCITY_DAMPING 1
#ifdef FORCE_VELOCITY_DAMPING
float speed = m_linearVelocity.length();
if (speed < m_linearDamping)
{
float dampVel = 0.005f;
if (speed > dampVel)
{
SimdVector3 dir = m_linearVelocity.normalized();
m_linearVelocity -= dir * dampVel;
} else
{
m_linearVelocity.setValue(0.f,0.f,0.f);
}
}
float angSpeed = m_angularVelocity.length();
if (angSpeed < m_angularDamping)
{
float angDampVel = 0.005f;
if (angSpeed > angDampVel)
{
SimdVector3 dir = m_angularVelocity.normalized();
m_angularVelocity -= dir * angDampVel;
} else
{
m_angularVelocity.setValue(0.f,0.f,0.f);
}
}
#endif //FORCE_VELOCITY_DAMPING
}
void btRigidBody::setDamping(btScalar lin_damping, btScalar ang_damping)
{
m_linearDamping = GEN_clamped(lin_damping, (btScalar)btScalar(0.0), (btScalar)btScalar(1.0));
m_angularDamping = GEN_clamped(ang_damping, (btScalar)btScalar(0.0), (btScalar)btScalar(1.0));
}
void RigidBody::setDamping(SimdScalar lin_damping, SimdScalar ang_damping)
{
m_linearDamping = GEN_clamped(lin_damping, 0.0f, 1.0f);
m_angularDamping = GEN_clamped(ang_damping, 0.0f, 1.0f);
}
