feature_levels_and_selectors.earth

<!--
osgEarth Sample
Shows how to use Levels and Selectors together when rendering feature data.
-->

<map name="Feature Geometry Demo" type="geocentric" version="2">

    <xi:include href="readymap_imagery.xml"/>
    
    <feature_model name="boundaries">
        <features name="world" driver="ogr">
            <url>../data/world.shp</url>
        </features>
        <styles>
            <style type="text/css">
                world {
                   stroke:       #9f9f7f;
                   stroke-width: 2px;
                   render-clip-plane: 0;
                   render-depth-test: false;
                }            
            </style>
        </styles>        
    </feature_model>    
    
    <feature_model name="cities">

        <features name="cities" driver="ogr">
            <url>../data/cities.gpkg</url>
        </features>
        
        <layout>
            <level name="far"    style="large"  max_range="1e10"/>
            <level name="medium" style="medium" max_range="3000000"/>
            <level name="close"  style="small"  max_range="200000"/>
        </layout>

        <styles>
            <selector name="large" class="label-large">
                <query>
                    <expr> <![CDATA[ rank_max >= 12 ]]> </expr>
                </query>
            </selector>
            
            <selector name="medium" class="label-medium">
                <query>
                    <expr> <![CDATA[ rank_max >= 8 AND rank_max < 12 ]]> </expr>
                </query>
            </selector>
            
            <selector name="small" class="label-small">
                <query>
                    <expr> <![CDATA[ rank_max < 8 ]]> </expr>
                </query>
            </selector>
            
            <style type="text/css">   
                label {
                    text-declutter: true;
                    text-content:   [name];
                    text-encoding:  utf-8;
                    text-align:     center_center;
                    text-priority:  [rank_max];
                    text-halo:      #2f2f2f;
                }                
                label-large : label {
                    text-size:      26.0;
                    text-color: #ffff00;
                }           
                label-medium : label {
                    text-size:      20.0;
                }           
                label-small : label {
                    text-size:      16.0;
                }     
            </style>
        </styles>
        
    </feature_model>
    
    <screen_space_layout>
        <sort_by_priority>true</sort_by_priority>
    </screen_space_layout>
  
</map>