/// Someone (ex. an ChExternalObject() ) may send this message to
/// the marker to tell that time has changed (even if simulation is
/// not running! - so it is different from the usual UpdateTime() -)
public void UpdatedExternalTime(double prevtime, double mtime)
{
double mstep = mtime - prevtime;
ChCoordsys m_rel_pos_dt = new ChCoordsys(new ChVector(0, 0, 0), new ChQuaternion(1, 0, 0, 0));
ChCoordsys m_rel_pos_dtdt = new ChCoordsys(new ChVector(0, 0, 0), new ChQuaternion(1, 0, 0, 0));
// do not try to switch on the M_MOTION_KEYFRAMED mode if
// we are already in the M_MOTION_EXTERNAL mode, maybe because
// a link point-surface is already moving the marker and
// it will handle the accelerations by itself
if (this.motion_type == eChMarkerMotion.M_MOTION_EXTERNAL)
{
return;
}
// otherwise see if a BDF is needed, cause an external 3rd party is moving the marker
this.motion_type = eChMarkerMotion.M_MOTION_FUNCTIONS;
// if POSITION or ROTATION ("rel_pos") has been changed in acceptable time step...
if ((!(ChVector.Vequal(FrameMoving.coord.pos, last_rel_coord.pos)) || !(ChQuaternion.Qequal(FrameMoving.coord.rot, last_rel_coord.rot))) && (Math.Abs(mstep) < 0.1) &&
(mstep != 0))
{
// ... and if motion wasn't caused by motion laws, then it was a keyframed movement!
if ((motion_X.Get_y(mtime) == 0) && (motion_Y.Get_y(mtime) == 0) && (motion_Z.Get_y(mtime) == 0) &&
(motion_ang.Get_y(mtime) == 0) && (motion_X.Get_Type() == ChFunction.FunctionType.FUNCT_CONST) &&
(motion_Y.Get_Type() == ChFunction.FunctionType.FUNCT_CONST) && (motion_Z.Get_Type() == ChFunction.FunctionType.FUNCT_CONST) &&
(motion_ang.Get_Type() == ChFunction.FunctionType.FUNCT_CONST))
{
// compute the relative speed by BDF !
m_rel_pos_dt.pos = ChVector.Vmul(ChVector.Vsub(FrameMoving.coord.pos, last_rel_coord.pos), 1 / mstep);
m_rel_pos_dt.rot = ChQuaternion.Qscale(ChQuaternion.Qsub(FrameMoving.coord.rot, last_rel_coord.rot), 1 / mstep);
// compute the relative acceleration by BDF !
m_rel_pos_dtdt.pos = ChVector.Vmul(ChVector.Vsub(m_rel_pos_dt.pos, last_rel_coord_dt.pos), 1 / mstep);
m_rel_pos_dtdt.rot = ChQuaternion.Qscale(ChQuaternion.Qsub(m_rel_pos_dt.rot, last_rel_coord_dt.rot), 1 / mstep);
// Set the position, speed and acceleration in relative space,
// automatically getting also the absolute values,
FrameMoving.SetCoord_dt(m_rel_pos_dt);
FrameMoving.SetCoord_dtdt(m_rel_pos_dtdt);
// update the remaining state variables
this.UpdateState();
// remember that the movement of this guy won't need further update
// of speed and acc. via motion laws!
this.motion_type = eChMarkerMotion.M_MOTION_KEYFRAMED;
}
}
// restore state buffers and that's all.
last_time = ChTime;
last_rel_coord = (ChCoordsys)FrameMoving.coord;
last_rel_coord_dt = (ChCoordsys)FrameMoving.coord_dt;
}
