<!--
osgEarth Sample

This map shows how to use the preemptive loading mode of osgearth. Preemptive
mode prioritizes the highest visible imagery LOD, skipping intermediate
levels. It also demonstrates per-layer resource allocation. Preemptive mode
uses a pool of loading threads to fetch tiles. You can use "loading_weight"
to give some layers more threads than others.

Please note that use of ESRI's free maps is subject to certain restrictions:
http://resources.esri.com/arcgisonlineservices/index.cfm?fa=content
-->

<map name="ESRI Imagery and Roads" type="geocentric" version="2">        

    <!-- Set a "preemptive" loading policy, and set the number of
         loading threads to use. -->
    <options>
        <terrain>
            <loading_policy mode="preemptive" loading_threads_per_core="3"/>
        </terrain>
    </options>
    
    <!-- loading_weight specifies the relative number of threads
         to use for this particular layer.  For heightfield layers,
         the highest specified loading_weight for all heightfield layers
         will be used.  For imagery layers, a separate group of threads
         will be allocated to handle each layer. -->
         
    <image name="arcgisonline esri imagery" driver="arcgis" loading_weight="1">
        <url>http://server.arcgisonline.com/ArcGIS/rest/services/ESRI_Imagery_World_2D/MapServer</url>
        <nodata_image>http://server.arcgisonline.com/ArcGIS/rest/services/ESRI_Imagery_World_2D/MapServer/tile/100/0/0.jpeg</nodata_image>
		<compress_textures>true</compress_textures>
    </image>
      
      
    <!-- We give the transportation layer 5x the resources as the image layer: -->
    
    <image name="arcgisonline transportation" driver="arcgis" loading_weight="5">
        <url>http://server.arcgisonline.com/ArcGIS/rest/services/Reference/ESRI_Transportation_World_2D/MapServer</url>
		<compress_textures>true</compress_textures>
    </image>
    
</map>
