C++ TextSymbol::priority方法代码示例

    /**
     * Creates a complete set of positioned label nodes from a feature list.
     */
    osg::Node* createNode(
        const FeatureList&   input,
        const Style&         style,
        FilterContext&       context )
    {
        if ( style.get<TextSymbol>() == 0L && style.get<IconSymbol>() == 0L )
            return 0L;

        // copy the style so we can (potentially) modify the text symbol.
        Style styleCopy = style;
        TextSymbol* text = styleCopy.get<TextSymbol>();
        IconSymbol* icon = styleCopy.get<IconSymbol>();

        osg::Group* group = new osg::Group();
        
        StringExpression  textContentExpr ( text ? *text->content()  : StringExpression() );
        NumericExpression textPriorityExpr( text ? *text->priority() : NumericExpression() );
        NumericExpression textSizeExpr    ( text ? *text->size()     : NumericExpression() );
        StringExpression  iconUrlExpr     ( icon ? *icon->url()      : StringExpression() );
        NumericExpression iconScaleExpr   ( icon ? *icon->scale()    : NumericExpression() );
        NumericExpression iconHeadingExpr ( icon ? *icon->heading()  : NumericExpression() );

        for( FeatureList::const_iterator i = input.begin(); i != input.end(); ++i )
        {
            Feature* feature = i->get();
            if ( !feature )
                continue;
            
            // run a symbol script if present.
            if ( text && text->script().isSet() )
            {
                StringExpression temp( text->script().get() );
                feature->eval( temp, &context );
            }
            
            // run a symbol script if present.
            if ( icon && icon->script().isSet() )
            {
                StringExpression temp( icon->script().get() );
                feature->eval( temp, &context );
            }

            const Geometry* geom = feature->getGeometry();
            if ( !geom )
                continue;

            Style tempStyle = styleCopy;

            // evaluate expressions into literals.
            // TODO: Later we could replace this with a generate "expression evaluator" type
            // that we could pass to PlaceNode in the DB options. -gw

            if ( text )
            {
                if ( text->content().isSet() )
                    tempStyle.get<TextSymbol>()->content()->setLiteral( feature->eval( textContentExpr, &context ) );

                if ( text->size().isSet() )
                    tempStyle.get<TextSymbol>()->size()->setLiteral( feature->eval(textSizeExpr, &context) );
            }

            if ( icon )
            {
                if ( icon->url().isSet() )
                    tempStyle.get<IconSymbol>()->url()->setLiteral( feature->eval(iconUrlExpr, &context) );

                if ( icon->scale().isSet() )
                    tempStyle.get<IconSymbol>()->scale()->setLiteral( feature->eval(iconScaleExpr, &context) );

                if ( icon->heading().isSet() )
                    tempStyle.get<IconSymbol>()->heading()->setLiteral( feature->eval(iconHeadingExpr, &context) );
            }
            
            osg::Node* node = makePlaceNode(
                context,
                feature,
                tempStyle,
                textPriorityExpr);

            if ( node )
            {
                if ( context.featureIndex() )
                {
                    context.featureIndex()->tagNode(node, feature);
                }

                group->addChild( node );
            }
        }

        // Note to self: need to change this to support picking later. -gw
        //VirtualProgram* vp = VirtualProgram::getOrCreate(group->getOrCreateStateSet());
        //vp->setInheritShaders( false );

        return group;
    }

//.........这里部分代码省略.........
        featureOptions.url() = "../data/world.shp";
    }
    else
    {
        // the --mem options tells us to just make an in-memory geometry:
        Ring* line = new Ring();
        line->push_back( osg::Vec3d(-60, 20, 0) );
        line->push_back( osg::Vec3d(-120, 20, 0) );
        line->push_back( osg::Vec3d(-120, 60, 0) );
        line->push_back( osg::Vec3d(-60, 60, 0) );
        featureOptions.geometry() = line;
    }

    // Define a style for the feature data. Since we are going to render the
    // vectors as lines, configure the line symbolizer:
    Style style;

    LineSymbol* ls = style.getOrCreateSymbol<LineSymbol>();
    ls->stroke()->color() = Color::Yellow;
    ls->stroke()->width() = 2.0f;

    // That's it, the map is ready; now create a MapNode to render the Map:
    MapNodeOptions mapNodeOptions;
    mapNodeOptions.enableLighting() = false;
    MapNode* mapNode = new MapNode( map, mapNodeOptions );

    osg::Group* root = new osg::Group();
    root->addChild( mapNode );
    viewer.setSceneData( root );
    viewer.setCameraManipulator( new EarthManipulator() );

    // Process cmdline args
    MapNodeHelper().parse(mapNode, arguments, &viewer, root, new LabelControl("Features Demo"));
   
    if (useStencil)
    {
        FeatureStencilModelOptions stencilOptions;
        stencilOptions.featureOptions() = featureOptions;
        stencilOptions.styles() = new StyleSheet();
        stencilOptions.styles()->addStyle( style );
        stencilOptions.enableLighting() = false;
        stencilOptions.depthTestEnabled() = false;
        ls->stroke()->width() = 0.1f;
        map->addModelLayer( new ModelLayer("my features", stencilOptions) );
    }
    else if (useRaster)
    {
        AGGLiteOptions rasterOptions;
        rasterOptions.featureOptions() = featureOptions;
        rasterOptions.styles() = new StyleSheet();
        rasterOptions.styles()->addStyle( style );
        map->addImageLayer( new ImageLayer("my features", rasterOptions) );
    }
    else //if (useGeom || useOverlay)
    {
        FeatureGeomModelOptions geomOptions;
        geomOptions.featureOptions() = featureOptions;
        geomOptions.styles() = new StyleSheet();
        geomOptions.styles()->addStyle( style );
        geomOptions.enableLighting() = false;

        ModelLayerOptions layerOptions( "my features", geomOptions );
        map->addModelLayer( new ModelLayer(layerOptions) );
    }

    if ( useLabels )
    {
        // set up symbology for drawing labels. We're pulling the label
        // text from the name attribute, and its draw priority from the
        // population attribute.
        Style labelStyle;

        TextSymbol* text = labelStyle.getOrCreateSymbol<TextSymbol>();
        text->content() = StringExpression( "[cntry_name]" );
        text->priority() = NumericExpression( "[pop_cntry]" );
        text->removeDuplicateLabels() = true;
        text->size() = 16.0f;
        text->alignment() = TextSymbol::ALIGN_CENTER_CENTER;
        text->fill()->color() = Color::White;
        text->halo()->color() = Color::DarkGray;

        // and configure a model layer:
        FeatureGeomModelOptions geomOptions;
        geomOptions.featureOptions() = featureOptions;
        geomOptions.styles() = new StyleSheet();
        geomOptions.styles()->addStyle( labelStyle );

        map->addModelLayer( new ModelLayer("labels", geomOptions) );
    }

    if ( !useStencil )
        viewer.getCamera()->addCullCallback( new osgEarth::Util::AutoClipPlaneCullCallback(mapNode) );

    // add some stock OSG handlers:
    viewer.addEventHandler(new osgViewer::StatsHandler());
    viewer.addEventHandler(new osgViewer::WindowSizeHandler());
    viewer.addEventHandler(new osgGA::StateSetManipulator(viewer.getCamera()->getOrCreateStateSet()));

    return viewer.run();
}

//.........这里部分代码省略.........
            if (p->second == "true") text->rotateToScreen() = true;
            else if (p->second == "false") text->rotateToScreen() = false;
        }
        else if (p->first == CSS_TEXT_SIZE_MODE)
        {
            if (!text) text = sc.getOrCreateSymbol<TextSymbol>();
            if (p->second == "screen") text->sizeMode() = TextSymbol::SIZEMODE_SCREEN;
            else if (p->second == "object") text->sizeMode() = TextSymbol::SIZEMODE_OBJECT;
        }
        else if (p->first == CSS_TEXT_REMOVE_DUPLICATE_LABELS)
        {
            if (!text) text = sc.getOrCreateSymbol<TextSymbol>();
            if (p->second == "true") text->removeDuplicateLabels() = true;
            else if (p->second == "false") text->removeDuplicateLabels() = false;
        } 
        else if (p->first == CSS_TEXT_LINE_ORIENTATION)
        {
            if (!text) text = sc.getOrCreateSymbol<TextSymbol>();
            if (p->second == "parallel") text->lineOrientation() = TextSymbol::LINEORIENTATION_PARALLEL;
            else if (p->second == "horizontal") text->lineOrientation() = TextSymbol::LINEORIENTATION_HORIZONTAL;
            else if (p->second == "perpendicular") text->lineOrientation() = TextSymbol::LINEORIENTATION_PERPENDICULAR;
        }
        else if (p->first == CSS_TEXT_LINE_PLACEMENT)
        {
            if (!text) text = sc.getOrCreateSymbol<TextSymbol>();
            if (p->second == "centroid") text->linePlacement() = TextSymbol::LINEPLACEMENT_CENTROID;
            else if (p->second == "along-line") text->linePlacement() = TextSymbol::LINEPLACEMENT_ALONG_LINE;
        }
        else if (p->first == "text-content")
        {
            if (!text) text = sc.getOrCreate<TextSymbol>();
            text->content() = StringExpression( p->second );
        }
        else if (p->first == "text-priority")
        {
            if (!text) text = sc.getOrCreateSymbol<TextSymbol>();
            text->priority() = NumericExpression( p->second );
        }
        else if (p->first == "text-provider")
        {
            if (!text) text = sc.getOrCreate<TextSymbol>();
            text->provider() = p->second;
        }

        //else if (p->first == CSS_TEXT_CONTENT)
        //{
        //    if (!text) text = sc.getOrCreateSymbol<TextSymbol>();
        //    text->content() = p->second;
        //}
        //else if (p->first == CSS_TEXT_CONTENT_ATTRIBUTE_DELIMITER)
        //{
        //    if (!text) text = sc.getOrCreateSymbol<TextSymbol>();
        //    text->contentAttributeDelimiter() = p->second;
        //}

        else if (p->first == "marker")
        {
            if (!marker) marker = sc.getOrCreateSymbol<MarkerSymbol>();
            marker->url() = p->second;
        }
        else if (p->first == "marker-placement")
        {
            if (!marker) marker = sc.getOrCreateSymbol<MarkerSymbol>();
            if      (p->second == "centroid") marker->placement() = MarkerSymbol::PLACEMENT_CENTROID;
            else if (p->second == "interval") marker->placement() = MarkerSymbol::PLACEMENT_INTERVAL;
            else if (p->second == "random"  ) marker->placement() = MarkerSymbol::PLACEMENT_RANDOM;

//
// NOTE: run this sample from the repo/tests directory.
//
int main(int argc, char** argv)
{
    osg::ArgumentParser arguments(&argc,argv);

    bool useRaster  = arguments.read("--rasterize");
    bool useOverlay = arguments.read("--overlay");
    bool useStencil = arguments.read("--stencil");
    bool useMem     = arguments.read("--mem");
    bool useLabels  = arguments.read("--labels");

    osgViewer::Viewer viewer(arguments);

    // Start by creating the map:
    Map* map = new Map();

    // Start with a basemap imagery layer; we'll be using the GDAL driver
    // to load a local GeoTIFF file:
    GDALOptions basemapOpt;
    basemapOpt.url() = "../data/world.tif";
    map->addImageLayer( new ImageLayer( ImageLayerOptions("basemap", basemapOpt) ) );

    // Next we add a feature layer. First configure a feature driver to 
    // load the vectors from a shapefile:
    OGRFeatureOptions featureOpt;
    if ( !useMem )
    {
        featureOpt.url() = "../data/usa.shp";
    }
    else
    {
        Ring* line = new Ring();
        line->push_back( osg::Vec3d(-60, 20, 0) );
        line->push_back( osg::Vec3d(-120, 20, 0) );
        line->push_back( osg::Vec3d(-120, 60, 0) );
        line->push_back( osg::Vec3d(-60, 60, 0) );
        featureOpt.geometry() = line;
    }

    // Define a style for the feature data. Since we are going to render the
    // vectors as lines, configure the line symbolizer:
    Style style;

    LineSymbol* ls = style.getOrCreateSymbol<LineSymbol>();
    ls->stroke()->color() = osg::Vec4f( 1,1,0,1 ); // yellow
    ls->stroke()->width() = 2.0f;

    // Add some text labels.
    if ( useLabels )
    {
        TextSymbol* text = style.getOrCreateSymbol<TextSymbol>();
        text->provider() = "overlay";
        text->content() = StringExpression( "[name]" );
        text->priority() = NumericExpression( "[area]" );
        text->removeDuplicateLabels() = true;
        text->size() = 16.0f;
        text->fill()->color() = Color::White;
        text->halo()->color() = Color::DarkGray;
    }

    // That's it, the map is ready; now create a MapNode to render the Map:
    MapNodeOptions mapNodeOptions;
    mapNodeOptions.enableLighting() = false;

    MapNode* mapNode = new MapNode( map, mapNodeOptions );

    // Now we'll choose the AGG-Lite driver to render the features. By the way, the
    // feature data is actually polygons, so we override that to treat it as lines.
    // We apply the feature driver and set the style as well.
    if (useStencil)
    {
        FeatureStencilModelOptions worldOpt;
        worldOpt.featureOptions() = featureOpt;
        worldOpt.geometryTypeOverride() = Geometry::TYPE_LINESTRING;
        worldOpt.styles() = new StyleSheet();
        worldOpt.styles()->addStyle( style );
        worldOpt.enableLighting() = false;
        worldOpt.depthTestEnabled() = false;
        map->addModelLayer( new ModelLayer( "my features", worldOpt ) );
    }
    else if (useRaster)
    {
        AGGLiteOptions worldOpt;
        worldOpt.featureOptions() = featureOpt;
        worldOpt.geometryTypeOverride() = Geometry::TYPE_LINESTRING;
        worldOpt.styles() = new StyleSheet();
        worldOpt.styles()->addStyle( style );
        map->addImageLayer( new ImageLayer( ImageLayerOptions("world", worldOpt) ) );
    }
    else //if (useGeom || useOverlay)
    {
        FeatureGeomModelOptions worldOpt;
        worldOpt.featureOptions() = featureOpt;
        worldOpt.geometryTypeOverride() = Geometry::TYPE_LINESTRING;
        worldOpt.styles() = new StyleSheet();
        worldOpt.styles()->addStyle( style );
        worldOpt.enableLighting() = false;
        worldOpt.depthTestEnabled() = false;
//.........这里部分代码省略.........