const Force::MobilityLinearSpring& Force::MobilityLinearSpring::
setStiffness(State& state, Real stiffness) const {
SimTK_ERRCHK1_ALWAYS(stiffness >= 0,
"Force::MobilityLinearSpring::setStiffness()",
"Stiffness coefficient must be nonnegative "
"(stiffness=%g).", stiffness);
getImpl().updParams(state).first = stiffness;
return *this;
}
Force::Gravity& Force::Gravity::
setDefaultMagnitude(Real g) {
SimTK_ERRCHK1_ALWAYS(g >= 0,
"Force::Gravity::setDefaultMagnitude()",
"The gravity magnitude g must be nonnegative but was specified as %g.",
g);
getImpl().invalidateTopologyCache();
updImpl().defMagnitude = g;
return *this;
}
const Force::MobilityLinearDamper& Force::MobilityLinearDamper::
setDamping(State& state, Real damping) const
{
SimTK_ERRCHK1_ALWAYS(damping >= 0,
"Force::MobilityLinearDamper::setDamping()",
"Damping coefficient must be nonnegative "
"(damping=%g).", damping);
getImpl().updDamping(state) = damping;
return *this;
}
Force::Gravity::Gravity
(GeneralForceSubsystem& forces,
const SimbodyMatterSubsystem& matter,
Real defMagnitude)
: Force(new GravityImpl(matter,defMagnitude,0))
{
SimTK_ERRCHK1_ALWAYS(defMagnitude >= 0,
"Force::Gravity::Gravity(magnitude)",
"The gravity magnitude g must be nonnegative but was specified as %g.",
defMagnitude);
updImpl().setForceSubsystem(forces, forces.adoptForce(*this));
}
Force::MobilityLinearDamper& Force::MobilityLinearDamper::
setDefaultDamping(Real defaultDamping) {
SimTK_ERRCHK1_ALWAYS(defaultDamping >= 0,
"Force::MobilityLinearDamper::setDefaultDamping()",
"Damping coefficient must be nonnegative "
"(defaultDamping=%g).", defaultDamping);
MobilityLinearDamperImpl& impl = updImpl();
if (impl.m_defaultDamping != defaultDamping) {
impl.m_defaultDamping = defaultDamping;
impl.invalidateTopologyCache();
}
return *this;
}
Force::MobilityLinearDamper::
MobilityLinearDamper(GeneralForceSubsystem& forces,
const MobilizedBody& mobod,
MobilizerUIndex whichU,
Real defaultDamping)
: Force(new MobilityLinearDamperImpl(mobod, whichU, defaultDamping))
{
SimTK_ERRCHK1_ALWAYS(defaultDamping >= 0,
"Force::MobilityLinearDamper::MobilityLinearDamper()",
"Damping coefficient must be nonnegative "
"(defaultDamping=%g).", defaultDamping);
updImpl().setForceSubsystem(forces, forces.adoptForce(*this));
}
Force::MobilityLinearSpring& Force::MobilityLinearSpring::
setDefaultStiffness(Real defaultStiffness) {
SimTK_ERRCHK1_ALWAYS(defaultStiffness >= 0,
"Force::MobilityLinearSpring::setDefaultStiffness()",
"Stiffness coefficient must be nonnegative "
"(defaultStiffness=%g).", defaultStiffness);
MobilityLinearSpringImpl& impl = updImpl();
if (impl.m_defaultStiffness != defaultStiffness) {
impl.m_defaultStiffness = defaultStiffness;
impl.invalidateTopologyCache();
}
return *this;
}
const Force::Gravity& Force::Gravity::
setMagnitude(State& state, Real g) const {
SimTK_ERRCHK1_ALWAYS(g >= 0,
"Force::Gravity::setMagnitude()",
"The gravity magnitude g must be nonnegative but was specified as %g.",
g);
if (getMagnitude(state) != g) {
getImpl().invalidateForceCache(state);
getImpl().updParameters(state).g = g;
if (g == 0)
getImpl().updForceCache(state).setToZero(); // must precalculate
}
return *this;
}
Force::MobilityLinearSpring::
MobilityLinearSpring(GeneralForceSubsystem& forces,
const MobilizedBody& mobod,
MobilizerQIndex whichQ,
Real defaultStiffness,
Real defaultQZero)
: Force(new MobilityLinearSpringImpl(mobod, whichQ,
defaultStiffness, defaultQZero))
{
SimTK_ERRCHK1_ALWAYS(defaultStiffness >= 0,
"Force::MobilityLinearSpring::MobilityLinearSpring()",
"Stiffness coefficient must be nonnegative "
"(defaultStiffness=%g).", defaultStiffness);
updImpl().setForceSubsystem(forces, forces.adoptForce(*this));
}
Force::Gravity::Gravity
(GeneralForceSubsystem& forces,
const SimbodyMatterSubsystem& matter,
const UnitVec3& defDirection,
Real defMagnitude,
Real defZeroHeight)
: Force(new GravityImpl(matter,defDirection,defMagnitude,defZeroHeight))
{
SimTK_ERRCHK1_ALWAYS(defMagnitude >= 0,
"Force::Gravity::Gravity(downDirection,magnitude)",
"The gravity magnitude g must be nonnegative but was specified as %g.",
defMagnitude);
SimTK_ERRCHK_ALWAYS(defDirection.isFinite(),
"Force::Gravity::Gravity(downDirection,magnitude)",
"A non-finite 'down' direction was received; did you specify a zero-"
"length Vec3? The direction must be non-zero.");
updImpl().setForceSubsystem(forces, forces.adoptForce(*this));
}
