예제 #1
0
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;
}
예제 #2
0
bool LoadSolarSystemObjects(istream& in,
                            Universe& universe,
                            const std::string& directory)
{
    Tokenizer tokenizer(&in);
    Parser parser(&tokenizer);

    while (tokenizer.nextToken() != Tokenizer::TokenEnd)
    {
        // Read the disposition; if none is specified, the default is Add.
        Disposition disposition = AddObject;
        if (tokenizer.getTokenType() == Tokenizer::TokenName)
        {
            if (tokenizer.getNameValue() == "Add")
            {
                disposition = AddObject;
                tokenizer.nextToken();
            }
            else if (tokenizer.getNameValue() == "Replace")
            {
                disposition = ReplaceObject;
                tokenizer.nextToken();
            }
            else if (tokenizer.getNameValue() == "Modify")
            {
                disposition = ModifyObject;
                tokenizer.nextToken();
            }
        }

        // Read the item type; if none is specified the default is Body
        string itemType("Body");
        if (tokenizer.getTokenType() == Tokenizer::TokenName)
        {
            itemType = tokenizer.getNameValue();
            tokenizer.nextToken();
        }

        if (tokenizer.getTokenType() != Tokenizer::TokenString)
        {
            sscError(tokenizer, "object name expected");
            return false;
        }
        
        // The name list is a string with zero more names. Multiple names are
        // delimited by colons.
        string nameList = tokenizer.getStringValue().c_str();

        if (tokenizer.nextToken() != Tokenizer::TokenString)
        {
            sscError(tokenizer, "bad parent object name");
            return false;
        }
        string parentName = tokenizer.getStringValue().c_str();

        Value* objectDataValue = parser.readValue();
        if (objectDataValue == NULL)
        {
            sscError(tokenizer, "bad object definition");
            return false;
        }

        if (objectDataValue->getType() != Value::HashType)
        {
            sscError(tokenizer, "{ expected");
            delete objectDataValue;
            return false;
        }
        Hash* objectData = objectDataValue->getHash();

        Selection parent = universe.findPath(parentName, NULL, 0);
        PlanetarySystem* parentSystem = NULL;
        
        vector<string> names;
        // Iterate through the string for names delimited
        // by ':', and insert them into the name list.
        if (nameList.empty())
        {
            names.push_back("");
        }
        else
        {
            string::size_type startPos   = 0;
            while (startPos != string::npos)
            {
                string::size_type next    = nameList.find(':', startPos);
                string::size_type length  = string::npos;
                if (next != string::npos)
                {
                    length   = next - startPos;
                    ++next;
                }
                names.push_back(nameList.substr(startPos, length));
                startPos   = next;
            }
        }
        string primaryName = names.front();

        BodyType bodyType = UnknownBodyType;
        if (itemType == "Body")
            bodyType = NormalBody;
        else if (itemType == "ReferencePoint")
            bodyType = ReferencePoint;
        else if (itemType == "SurfaceObject")
            bodyType = SurfaceObject;
        
        if (bodyType != UnknownBodyType)
        {
            //bool orbitsPlanet = false;
            if (parent.star() != NULL)
            {
                SolarSystem* solarSystem = universe.getSolarSystem(parent.star());
                if (solarSystem == NULL)
                {
                    // No solar system defined for this star yet, so we need
                    // to create it.
                    solarSystem = universe.createSolarSystem(parent.star());
                }
                parentSystem = solarSystem->getPlanets();
            }
            else if (parent.body() != NULL)
            {
                // Parent is a planet or moon
                parentSystem = parent.body()->getSatellites();
                if (parentSystem == NULL)
                {
                    // If the planet doesn't already have any satellites, we
                    // have to create a new planetary system for it.
                    parentSystem = new PlanetarySystem(parent.body());
                    parent.body()->setSatellites(parentSystem);
                }
                //orbitsPlanet = true;
            }
            else
            {
                errorMessagePrelude(tokenizer);
                cerr << _("parent body '") << parentName << _("' of '") << primaryName << _("' not found.") << endl;
            }

            if (parentSystem != NULL)
            {
                Body* existingBody = parentSystem->find(primaryName);
                if (existingBody)
                {
                    if (disposition == AddObject)
                    {
                        errorMessagePrelude(tokenizer);
                        cerr << _("warning duplicate definition of ") <<
                            parentName << " " <<  primaryName << '\n';
                    }
                    else if (disposition == ReplaceObject)
                    {
                        existingBody->setDefaultProperties();
                    }
                }

                Body* body;
                if (bodyType == ReferencePoint)
                    body = CreateReferencePoint(primaryName, parentSystem, universe, existingBody, objectData, directory, disposition);
                else
                    body = CreateBody(primaryName, parentSystem, universe, existingBody, objectData, directory, disposition, bodyType);
                
                if (body != NULL && disposition == AddObject)
                {
                    vector<string>::const_iterator iter = names.begin();
                    iter++;
                    while (iter != names.end())
                    {
                        body->addAlias(*iter);
                        iter++;
                    }
                }
            }
        }
        else if (itemType == "AltSurface")
        {
            Surface* surface = new Surface();
            surface->color = Color(1.0f, 1.0f, 1.0f);
            surface->hazeColor = Color(0.0f, 0.0f, 0.0f, 0.0f);
            FillinSurface(objectData, surface, directory);
            if (surface != NULL && parent.body() != NULL)
                parent.body()->addAlternateSurface(primaryName, surface);
            else
                sscError(tokenizer, _("bad alternate surface"));
        }
        else if (itemType == "Location")
        {
            if (parent.body() != NULL)
            {
                Location* location = CreateLocation(objectData, parent.body());
                if (location != NULL)
                {
                    location->setName(primaryName);
                    parent.body()->addLocation(location);
                }
                else
                {
                    sscError(tokenizer, _("bad location"));
                }
            }
            else
            {
                errorMessagePrelude(tokenizer);
                cerr << _("parent body '") << parentName << _("' of '") << primaryName << _("' not found.\n");
            }
        }
        delete objectDataValue;
    }

    // TODO: Return some notification if there's an error parsing the file
    return true;
}