void Frame::UpdateOrbitRails(double time, double timestep)
{
m_oldPos = m_pos;
m_oldAngDisplacement = m_angSpeed * timestep;
// update frame position and velocity
if (m_parent && m_sbody && !IsRotFrame()) {
m_pos = m_sbody->orbit.OrbitalPosAtTime(time);
vector3d pos2 = m_sbody->orbit.OrbitalPosAtTime(time+timestep);
m_vel = (pos2 - m_pos) / timestep;
}
// temporary test thing
else m_pos = m_pos + m_vel * timestep;
// update frame rotation
double ang = m_angSpeed * timestep; // hmm. cumulative inaccuracy? worse!
if (!is_zero_exact(ang)) { // frequently used with e^-10 etc
matrix3x3d rot = matrix3x3d::RotateY(-ang); // RotateY is backwards
m_orient = m_orient * rot; // angvel always +y
}
UpdateRootRelativeVars(); // update root-relative pos/vel/orient
for (ChildIterator it = m_children.begin(); it != m_children.end(); ++it)
(*it)->UpdateOrbitRails(time, timestep);
}
void Frame::ClearMovement()
{
UpdateRootRelativeVars();
m_rootInterpPos = m_rootPos;
m_rootInterpOrient = m_rootOrient;
m_oldPos = m_interpPos = m_pos;
m_interpOrient = m_orient;
m_oldAngDisplacement = 0.0;
}
