[ODE] Set joint forces/torques directly

[Martin C. Martin]

Hi all,

I've added some new utility functions to ODE, along with some
documentation for them.  Here's the documentation.

Enjoy,
Martin


Setting Joint Torques/Forces Directly

Motors (see above) allow you to set joint velocities directly.  However,
you 
may instead wish to set the torque or force at a joint instead.  These 
functions do just that.  Note that they don't affect the motor, but simply
call @func{dBodyAddForce()}/@func{dBodyAddTorque()} on the bodies attached
to
it.

@funcdef{dJointAddHingeTorque(dJointID joint, dReal torque)}

Applies the torque about the hinge axis.  That is, it applies a torque
with
magnitude @arg{torque}, in the direction of the hinge axis, to body 1, and 
with the same magnitude but in opposite direction to body 2.  This
function 
is just a wrapper for @func{dBodyAddTorque()}

@funcdef{dJointAddUniversalTorques(dJointID joint, dReal torque1, dReal
torque2)}

Applies @arg{torque1} about the universal's axis 1, and @arg{torque2}
about the
universal's axis 2.  This function is just a wrapper for
@func{dBodyAddTorque()}.

@funcdef{dJointAddSliderForce(dJointID joint, dReal force)}

Applies the given force in the slider's direction.  That is, it applies a
force
with magnitude @arg{force}, in the direction slider's axis, to body1, and
with 
the same magnitude but oppsite direction to body2.  This function is just
a 
wrapper for @func{dBodyAddForce()}.

@funcdef{dJointAddHinge2Torqe(dJointID joint, dReal torque1, dReal
torque2)}

Applies @arg{torque1} about the hinge2's axis 1, and @arg{torque2} about
the 
hinge2's axis 2.  This function is just a wrapper for
@func{dBodyAddTorque()}.

@funcdef{dJointAddAMotorTorque(dJointID joint, dReal torque0, dReal
torque1, dReal torque2)}

Applies @arg{torque0} about the AMotor's axis 0, @arg{torque1} about the 
AMotor's axis 1, and @arg{torque2} about the AMotor's axis 2.  If the
motor has
fewer than three axes, the higher torques are ignored.  This function is
just a
wrapper for @func{dBodyAddTorque()}.