void
ElevationQuery::reset()
{
    // set read callback for IntersectionVisitor
    _ivrc = new osgSim::DatabaseCacheReadCallback();

    _terrainModelLayers.clear();
    _elevationLayers.clear();

    osg::ref_ptr<const Map> map;
    if (_map.lock(map))
    {
        map->getLayers(_elevationLayers);
        
        // cache a vector of terrain patch models.
        LayerVector layers;
        map->getLayers(layers);
        for (LayerVector::const_iterator i = layers.begin(); i != layers.end(); ++i)
        {
            if (i->get()->options().terrainPatch() == true)
            {
                _terrainModelLayers.push_back(i->get());
            }
        }

        // revisions are now in sync.
        _mapRevision = map->getDataModelRevision();
    }

    // clear any active envelope
    _envelope = 0L;
}

bool
MapFrame::sync()
{
    bool changed = false;
    _elevationLayers.clear();

    osg::ref_ptr<const Map> map;
    if ( _map.lock(map) )
    {
        changed = map->sync( *this );
        if ( changed )
        {
            refreshComputedValues();
        }
        _pool = map->getElevationPool();
    }
    else
    {
        _layers.clear();
    }

    for (LayerVector::const_iterator i = _layers.begin(); i != _layers.end(); ++i)
    {
        ElevationLayer* e = dynamic_cast<ElevationLayer*>(i->get());
        if (e)
            _elevationLayers.push_back(e);
    }
    

    return changed;
}

void
MapFrame::refreshComputedValues()
{
    _highestMinLevel = 0;

    _elevationLayers.clear();

    for (LayerVector::const_iterator i = _layers.begin(); i != _layers.end(); ++i)
    {
        TerrainLayer* terrainLayer = dynamic_cast<TerrainLayer*>(i->get());
        if (terrainLayer)
        {
            const optional<unsigned>& minLevel = terrainLayer->getTerrainLayerRuntimeOptions().minLevel();
            if (minLevel.isSet() && minLevel.value() > _highestMinLevel)
            {
                _highestMinLevel = minLevel.value();
            }

            ElevationLayer* elevation = dynamic_cast<ElevationLayer*>(terrainLayer);
            if (elevation)
            {
                _elevationLayers.push_back(elevation);
            }
        }
    }
}

Config
EarthFileSerializer2::serialize(const MapNode* input, const std::string& referrer) const
{
    Config mapConf("map");
    mapConf.set("version", "2");

    if ( !input || !input->getMap() )
        return mapConf; 

    const Map* map = input->getMap();
    MapFrame mapf( map );

    // the map and node options:
    Config optionsConf = map->getInitialMapOptions().getConfig();
    optionsConf.merge( input->getMapNodeOptions().getConfig() );
    mapConf.add( "options", optionsConf );

    // the layers
    LayerVector layers;
    mapf.getLayers(layers);

    for (LayerVector::const_iterator i = layers.begin(); i != layers.end(); ++i)
    {
        const Layer* layer = i->get();

        Config layerConf = layer->getConfig();
        if (!layerConf.empty())
        {
            mapConf.add(layerConf);
        }
    }

    typedef std::vector< osg::ref_ptr<Extension> > Extensions;
    for(Extensions::const_iterator i = input->getExtensions().begin(); i != input->getExtensions().end(); ++i)
    {
        Extension* e = i->get();
        Config conf = e->getConfigOptions().getConfig();
        if ( !conf.key().empty() )
        {
            mapConf.add( conf );
        }
    }

    Config ext = input->externalConfig();
    if ( !ext.empty() )
    {
        ext.key() = "external";
        mapConf.add( ext );
    }

    // Re-write pathnames in the Config so they are relative to the new referrer.
    if ( _rewritePaths && !referrer.empty() )
    {
        RewritePaths rewritePaths( referrer );
        rewritePaths.setRewriteAbsolutePaths( _rewriteAbsolutePaths );
        rewritePaths.apply( mapConf );
    }

    return mapConf;
}

bool
MapFrame::containsLayer(UID uid) const
{
    for (LayerVector::const_iterator i = _layers.begin(); i != _layers.end(); ++i)
        if (i->get()->getUID() == uid)
            return true;
    return false;
}

bool
MapFrame::containsEnabledLayer(UID uid) const
{
    for (LayerVector::const_iterator i = _layers.begin(); i != _layers.end(); ++i)
    {
        if (i->get()->getUID() == uid)
        {
            return i->get()->getEnabled();
        }
    }
    return false;
}

void
TerrainTileModelFactory::addColorLayers(TerrainTileModel* model,
                                        const Map* map,
                                        const TerrainEngineRequirements* reqs,
                                        const TileKey&    key,
                                        const CreateTileModelFilter& filter,
                                        ProgressCallback* progress)
{
    OE_START_TIMER(fetch_image_layers);

    int order = 0;

    LayerVector layers;
    map->getLayers(layers);

    for (LayerVector::const_iterator i = layers.begin(); i != layers.end(); ++i)
    {
        Layer* layer = i->get();

        if (layer->getRenderType() != layer->RENDERTYPE_TERRAIN_SURFACE)
            continue;

        if (!layer->getEnabled())
            continue;

        if (!filter.accept(layer))
            continue;

        ImageLayer* imageLayer = dynamic_cast<ImageLayer*>(layer);
        if (imageLayer)
        {
            osg::Texture* tex = 0L;
            osg::Matrixf textureMatrix;

            if (imageLayer->isKeyInLegalRange(key) && imageLayer->mayHaveDataInExtent(key.getExtent()))
            {
                if (imageLayer->createTextureSupported())
                {
                    tex = imageLayer->createTexture( key, progress, textureMatrix );
                }

                else
                {
                    GeoImage geoImage = imageLayer->createImage( key, progress );
           
                    if ( geoImage.valid() )
                    {
                        if ( imageLayer->isCoverage() )
                            tex = createCoverageTexture(geoImage.getImage(), imageLayer);
                        else
                            tex = createImageTexture(geoImage.getImage(), imageLayer);
                    }
                }
            }
        
            // if this is the first LOD, and the engine requires that the first LOD
            // be populated, make an empty texture if we didn't get one.
            if (tex == 0L &&
                _options.firstLOD() == key.getLOD() &&
                reqs && reqs->fullDataAtFirstLodRequired())
            {
                tex = _emptyTexture.get();
            }
         
            if (tex)
            {
                tex->setName(model->getKey().str());

                TerrainTileImageLayerModel* layerModel = new TerrainTileImageLayerModel();

                layerModel->setImageLayer(imageLayer);

                layerModel->setTexture(tex);
                layerModel->setMatrix(new osg::RefMatrixf(textureMatrix));

                model->colorLayers().push_back(layerModel);

                if (imageLayer->isShared())
                {
                    model->sharedLayers().push_back(layerModel);
                }

                if (imageLayer->isDynamic())
                {
                    model->setRequiresUpdateTraverse(true);
                }
            }
        }

        else // non-image kind of TILE layer:
        {
            TerrainTileColorLayerModel* colorModel = new TerrainTileColorLayerModel();
            colorModel->setLayer(layer);
            model->colorLayers().push_back(colorModel);
        }
    }

    if (progress)
        progress->stats()["fetch_imagery_time"] += OE_STOP_TIMER(fetch_image_layers);
}

void
TerrainRenderData::setup(const MapFrame& frame,
                         const RenderBindings& bindings,
                         unsigned frameNum,
                         osgUtil::CullVisitor* cv)
{
    _bindings = &bindings;

    // Create a new State object to track sampler and uniform settings
    _drawState = new DrawState();
    _drawState->_frame = frameNum;
    _drawState->_bindings = &bindings;

    // Make a drawable for each rendering pass (i.e. each render-able map layer).
    for(LayerVector::const_iterator i = frame.layers().begin();
        i != frame.layers().end();
        ++i)
    {
        Layer* layer = i->get();
        if (layer->getEnabled())
        {
            if (layer->getRenderType() == Layer::RENDERTYPE_TILE ||
                layer->getRenderType() == Layer::RENDERTYPE_PATCH)
            {
                bool render = true;

                // If this is an image layer, check the enabled/visible states.
                VisibleLayer* visLayer = dynamic_cast<VisibleLayer*>(layer);
                if (visLayer)
                {
                    render = visLayer->getVisible();
                }

                if (render)
                {
                    ImageLayer* imgLayer = dynamic_cast<ImageLayer*>(layer);

                    // Make a list of "global" layers. There are layers whose data is not
                    // represented in the TerrainTileModel, like a splatting layer or a patch
                    // layer. The data for these is dynamic and not based on data fetched.
                    if (imgLayer == 0L && layer->getRenderType() == Layer::RENDERTYPE_TILE)
                    {
                        tileLayers().push_back(layer);
                        addLayerDrawable(layer);
                    }
                    else if (layer->getRenderType() == Layer::RENDERTYPE_PATCH)
                    {
                        PatchLayer* patchLayer = static_cast<PatchLayer*>(layer); // asumption!

                        if (patchLayer->getAcceptCallback() != 0L &&
                            patchLayer->getAcceptCallback()->acceptLayer(*cv, cv->getCurrentCamera()))
                        {
                            patchLayers().push_back(dynamic_cast<PatchLayer*>(layer));
                            addLayerDrawable(layer);
                        }
                    }
                    else
                    {
                        addLayerDrawable(layer);
                    }
                }
            }
        }
    }

    // Include a "blank" layer for missing data.
    LayerDrawable* blank = addLayerDrawable(0L);
    blank->getOrCreateStateSet()->setDefine("OE_TERRAIN_RENDER_IMAGERY", osg::StateAttribute::OFF);
}

void
TerrainRenderData::setup(const Map* map,
                         const RenderBindings& bindings,
                         unsigned frameNum,
                         osgUtil::CullVisitor* cv)
{
    _bindings = &bindings;

    // Create a new State object to track sampler and uniform settings
    _drawState = new DrawState();
    _drawState->_frame = frameNum;
    _drawState->_bindings = &bindings;
    
    // Is this a depth camera? Because if it is, we don't need any color layers.
    const osg::Camera* cam = cv->getCurrentCamera();
    bool isDepthCamera = ClampableNode::isDepthCamera(cam);

    // Make a drawable for each rendering pass (i.e. each render-able map layer).
    LayerVector layers;
    map->getLayers(layers);

    for (LayerVector::const_iterator i = layers.begin(); i != layers.end(); ++i)
    {
        Layer* layer = i->get();
        if (layer->getEnabled())
        {
            bool render =
                (layer->getRenderType() == Layer::RENDERTYPE_TERRAIN_SURFACE) || // && !isDepthCamera) ||
                (layer->getRenderType() == Layer::RENDERTYPE_TERRAIN_PATCH);

            if ( render )
            {
                // If this is an image layer, check the enabled/visible states.
                VisibleLayer* visLayer = dynamic_cast<VisibleLayer*>(layer);
                if (visLayer)
                {
                    render = visLayer->getVisible();
                }

                if (render)
                {
                    if (layer->getRenderType() == Layer::RENDERTYPE_TERRAIN_SURFACE)
                    {
                        LayerDrawable* ld = addLayerDrawable(layer);

                        // If the current camera is depth-only, leave this layer in the set
                        // but mark it as no-draw. We keep it in the set so the culler doesn't
                        // inadvertently think it's an orphaned layer.
                        if (isDepthCamera)
                        {
                            ld->_draw = false;
                        }
                    }

                    else // if (layer->getRenderType() == Layer::RENDERTYPE_TERRAIN_PATCH)
                    {
                        PatchLayer* patchLayer = static_cast<PatchLayer*>(layer); // asumption!

                        if (patchLayer->getAcceptCallback() != 0L &&
                            patchLayer->getAcceptCallback()->acceptLayer(*cv, cv->getCurrentCamera()))
                        {
                            patchLayers().push_back(dynamic_cast<PatchLayer*>(layer));
                            addLayerDrawable(layer);
                        }
                    }
                }
            }
        }
    }

    // Include a "blank" layer for missing data.
    LayerDrawable* blank = addLayerDrawable(0L);
}