TimelinePhase* CreateTimelinePhase(Body* body,
Universe& universe,
Hash* phaseData,
const string& path,
ReferenceFrame* defaultOrbitFrame,
ReferenceFrame* defaultBodyFrame,
bool isFirstPhase,
bool isLastPhase,
double previousPhaseEnd)
{
double beginning = previousPhaseEnd;
double ending = numeric_limits<double>::infinity();
// Beginning is optional for the first phase of a timeline, and not
// allowed for the other phases, where beginning is always the ending
// of the previous phase.
bool hasBeginning = ParseDate(phaseData, "Beginning", beginning);
if (!isFirstPhase && hasBeginning)
{
clog << "Error: Beginning can only be specified for initial phase of timeline.\n";
return NULL;
}
// Ending is required for all phases except for the final one.
bool hasEnding = ParseDate(phaseData, "Ending", ending);
if (!isLastPhase && !hasEnding)
{
clog << "Error: Ending is required for all timeline phases other than the final one.\n";
return NULL;
}
// Get the orbit reference frame.
ReferenceFrame* orbitFrame;
Value* frameValue = phaseData->getValue("OrbitFrame");
if (frameValue != NULL)
{
orbitFrame = CreateReferenceFrame(universe, frameValue, defaultOrbitFrame->getCenter(), body);
if (orbitFrame == NULL)
{
return NULL;
}
}
else
{
// No orbit frame specified; use the default frame.
orbitFrame = defaultOrbitFrame;
}
orbitFrame->addRef();
// Get the body reference frame
ReferenceFrame* bodyFrame;
Value* bodyFrameValue = phaseData->getValue("BodyFrame");
if (bodyFrameValue != NULL)
{
bodyFrame = CreateReferenceFrame(universe, bodyFrameValue, defaultBodyFrame->getCenter(), body);
if (bodyFrame == NULL)
{
orbitFrame->release();
return NULL;
}
}
else
{
// No body frame specified; use the default frame.
bodyFrame = defaultBodyFrame;
}
bodyFrame->addRef();
// Use planet units (AU for semimajor axis) if the center of the orbit
// reference frame is a star.
bool usePlanetUnits = orbitFrame->getCenter().star() != NULL;
// Get the orbit
Orbit* orbit = CreateOrbit(orbitFrame->getCenter(), phaseData, path, usePlanetUnits);
if (!orbit)
{
clog << "Error: missing orbit in timeline phase.\n";
bodyFrame->release();
orbitFrame->release();
return NULL;
}
// Get the rotation model
// TIMELINE-TODO: default rotation model is UniformRotation with a period
// equal to the orbital period. Should we do something else?
RotationModel* rotationModel = CreateRotationModel(phaseData, path, orbit->getPeriod());
if (!rotationModel)
{
// TODO: Should distinguish between a missing rotation model (where it's
// appropriate to use a default one) and a bad rotation model (where
// we should report an error.)
rotationModel = new ConstantOrientation(Quaterniond::Identity());
}
TimelinePhase* phase = TimelinePhase::CreateTimelinePhase(universe,
body,
beginning, ending,
*orbitFrame,
*orbit,
*bodyFrame,
*rotationModel);
// Frame ownership transfered to phase; release local references
orbitFrame->release();
bodyFrame->release();
return phase;
}
