Timeline* CreateTimelineFromArray(Body* body,
Universe& universe,
ValueArray* timelineArray,
const string& path,
ReferenceFrame* defaultOrbitFrame,
ReferenceFrame* defaultBodyFrame)
{
Timeline* timeline = new Timeline();
double previousEnding = -numeric_limits<double>::infinity();
for (ValueArray::const_iterator iter = timelineArray->begin(); iter != timelineArray->end(); iter++)
{
Hash* phaseData = (*iter)->getHash();
if (phaseData == NULL)
{
clog << "Error in timeline of '" << body->getName() << "': phase " << iter - timelineArray->begin() + 1 << " is not a property group.\n";
delete timeline;
return NULL;
}
bool isFirstPhase = iter == timelineArray->begin();
bool isLastPhase = *iter == timelineArray->back();
TimelinePhase* phase = CreateTimelinePhase(body, universe, phaseData,
path,
defaultOrbitFrame,
defaultBodyFrame,
isFirstPhase, isLastPhase, previousEnding);
if (phase == NULL)
{
clog << "Error in timeline of '" << body->getName() << "', phase " << iter - timelineArray->begin() + 1 << endl;
delete timeline;
return NULL;
}
previousEnding = phase->endTime();
timeline->appendPhase(phase);
}
return timeline;
}
static bool CreateTimeline(Body* body,
PlanetarySystem* system,
Universe& universe,
Hash* planetData,
const string& path,
Disposition disposition,
BodyType bodyType)
{
FrameTree* parentFrameTree = NULL;
Selection parentObject = GetParentObject(system);
bool orbitsPlanet = false;
if (parentObject.body())
{
parentFrameTree = parentObject.body()->getOrCreateFrameTree();
orbitsPlanet = true;
}
else if (parentObject.star())
{
SolarSystem* solarSystem = universe.getSolarSystem(parentObject.star());
if (solarSystem == NULL)
solarSystem = universe.createSolarSystem(parentObject.star());
parentFrameTree = solarSystem->getFrameTree();
}
else
{
// Bad orbit barycenter specified
return false;
}
ReferenceFrame* defaultOrbitFrame = NULL;
ReferenceFrame* defaultBodyFrame = NULL;
if (bodyType == SurfaceObject)
{
defaultOrbitFrame = new BodyFixedFrame(parentObject, parentObject);
defaultBodyFrame = CreateTopocentricFrame(parentObject, parentObject, Selection(body));
defaultOrbitFrame->addRef();
defaultBodyFrame->addRef();
}
else
{
defaultOrbitFrame = parentFrameTree->getDefaultReferenceFrame();
defaultBodyFrame = parentFrameTree->getDefaultReferenceFrame();
}
// If there's an explicit timeline definition, parse that. Otherwise, we'll do
// things the old way.
Value* value = planetData->getValue("Timeline");
if (value != NULL)
{
if (value->getType() != Value::ArrayType)
{
clog << "Error: Timeline must be an array\n";
return false;
}
Timeline* timeline = CreateTimelineFromArray(body, universe, value->getArray(), path,
defaultOrbitFrame, defaultBodyFrame);
if (timeline == NULL)
{
return false;
}
else
{
body->setTimeline(timeline);
return true;
}
}
// Information required for the object timeline.
ReferenceFrame* orbitFrame = NULL;
ReferenceFrame* bodyFrame = NULL;
Orbit* orbit = NULL;
RotationModel* rotationModel = NULL;
double beginning = -numeric_limits<double>::infinity();
double ending = numeric_limits<double>::infinity();
// If any new timeline values are specified, we need to overrideOldTimeline will
// be set to true.
bool overrideOldTimeline = false;
// The interaction of Modify with timelines is slightly complicated. If the timeline
// is specified by putting the OrbitFrame, Orbit, BodyFrame, or RotationModel directly
// in the object definition (i.e. not inside a Timeline structure), it will completely
// replace the previous timeline if it contained more than one phase. Otherwise, the
// properties of the single phase will be modified individually, for compatibility with
// Celestia versions 1.5.0 and earlier.
if (disposition == ModifyObject)
{
const Timeline* timeline = body->getTimeline();
if (timeline->phaseCount() == 1)
{
const TimelinePhase* phase = timeline->getPhase(0);
orbitFrame = phase->orbitFrame();
bodyFrame = phase->bodyFrame();
orbit = phase->orbit();
rotationModel = phase->rotationModel();
beginning = phase->startTime();
ending = phase->endTime();
}
}
// Get the object's orbit reference frame.
bool newOrbitFrame = false;
Value* frameValue = planetData->getValue("OrbitFrame");
if (frameValue != NULL)
{
ReferenceFrame* frame = CreateReferenceFrame(universe, frameValue, parentObject, body);
if (frame != NULL)
{
orbitFrame = frame;
newOrbitFrame = true;
overrideOldTimeline = true;
}
}
// Get the object's body frame.
bool newBodyFrame = false;
Value* bodyFrameValue = planetData->getValue("BodyFrame");
if (bodyFrameValue != NULL)
{
ReferenceFrame* frame = CreateReferenceFrame(universe, bodyFrameValue, parentObject, body);
if (frame != NULL)
{
bodyFrame = frame;
newBodyFrame = true;
overrideOldTimeline = true;
}
}
// If no orbit or body frame was specified, use the default ones
if (orbitFrame == NULL)
orbitFrame = defaultOrbitFrame;
if (bodyFrame == NULL)
bodyFrame = defaultBodyFrame;
// If the center of the is a star, orbital element units are
// in AU; otherwise, use kilometers.
if (orbitFrame->getCenter().star() != NULL)
orbitsPlanet = false;
else
orbitsPlanet = true;
Orbit* newOrbit = CreateOrbit(orbitFrame->getCenter(), planetData, path, !orbitsPlanet);
if (newOrbit == NULL && orbit == NULL)
{
if (body->getTimeline() && disposition == ModifyObject)
{
// The object definition is modifying an existing object with a multiple phase
// timeline, but no orbit definition was given. This can happen for completely
// sensible reasons, such a Modify definition that just changes visual properties.
// Or, the definition may try to change other timeline phase properties such as
// the orbit frame, but without providing an orbit. In both cases, we'll just
// leave the original timeline alone.
return true;
}
else
{
clog << "No valid orbit specified for object '" << body->getName() << "'. Skipping.\n";
return false;
}
}
// If a new orbit was given, override any old orbit
if (newOrbit != NULL)
{
orbit = newOrbit;
overrideOldTimeline = true;
}
// Get the rotation model for this body
double syncRotationPeriod = orbit->getPeriod();
RotationModel* newRotationModel = CreateRotationModel(planetData, path, syncRotationPeriod);
// If a new rotation model was given, override the old one
if (newRotationModel != NULL)
{
rotationModel = newRotationModel;
overrideOldTimeline = true;
}
// If there was no rotation model specified, nor a previous rotation model to
// override, create the default one.
if (rotationModel == NULL)
{
// If no rotation model is provided, use a default rotation model--
// a uniform rotation that's synchronous with the orbit (appropriate
// for nearly all natural satellites in the solar system.)
rotationModel = CreateDefaultRotationModel(syncRotationPeriod);
}
if (ParseDate(planetData, "Beginning", beginning))
overrideOldTimeline = true;
if (ParseDate(planetData, "Ending", ending))
overrideOldTimeline = true;
// Something went wrong if the disposition isn't modify and no timeline
// is to be created.
assert(disposition == ModifyObject || overrideOldTimeline);
if (overrideOldTimeline)
{
if (beginning >= ending)
{
clog << "Beginning time must be before Ending time.\n";
return false;
}
// We finally have an orbit, rotation model, frames, and time range. Create
// the object timeline.
TimelinePhase* phase = TimelinePhase::CreateTimelinePhase(universe,
body,
beginning, ending,
*orbitFrame,
*orbit,
*bodyFrame,
*rotationModel);
// We've already checked that beginning < ending; nothing else should go
// wrong during the creation of a TimelinePhase.
assert(phase != NULL);
if (phase == NULL)
{
clog << "Internal error creating TimelinePhase.\n";
return false;
}
Timeline* timeline = new Timeline();
timeline->appendPhase(phase);
body->setTimeline(timeline);
// Check for circular references in frames; this can only be done once the timeline
// has actually been set.
// TIMELINE-TODO: This check is not comprehensive; it won't find recursion in
// multiphase timelines.
if (newOrbitFrame && isFrameCircular(*body->getOrbitFrame(0.0), ReferenceFrame::PositionFrame))
{
clog << "Orbit frame for " << body->getName() << " is nested too deep (probably circular)\n";
return false;
}
if (newBodyFrame && isFrameCircular(*body->getBodyFrame(0.0), ReferenceFrame::OrientationFrame))
{
clog << "Body frame for " << body->getName() << " is nested too deep (probably circular)\n";
return false;
}
}
return true;
}