trailpack-mapnik/test/xml/hybrid_basemap.xml

Mapnik Tile Server with Trails.js

<Map srs="+init=epsg:3857" background-color="#ffffffff">
  <Parameters>
    <Parameter name="format">png8</Parameter>
    <Parameter name="tileSize">512</Parameter>
    <Parameter name="width">512</Parameter>
    <Parameter name="height">512</Parameter>
    <Parameter name="minzoom">2</Parameter>
    <Parameter name="maxzoom">18</Parameter>
  </Parameters>

  <Style name="aerial_raster_1ft">
    <Rule>
      <MaxScaleDenominator>20000</MaxScaleDenominator>
      <MinScaleDenominator>12000</MinScaleDenominator>
      <RasterSymbolizer opacity="0.60" />
    </Rule>
    <Rule>
      <MaxScaleDenominator>12000</MaxScaleDenominator>
      <MinScaleDenominator>6000</MinScaleDenominator>
      <RasterSymbolizer opacity="0.75" />
    </Rule>
    <Rule>
      <MaxScaleDenominator>6000</MaxScaleDenominator>
      <MinScaleDenominator>4000</MinScaleDenominator>
      <RasterSymbolizer opacity="0.90" />
    </Rule>
    <Rule>
      <MaxScaleDenominator>4000</MaxScaleDenominator>
      <RasterSymbolizer opacity="1.0" />
    </Rule>
  </Style>

  <Style name="basemap" image-filters="color-to-alpha(#fff)">
    <Rule>
      <RasterSymbolizer opacity="1.0" />
    </Rule>
  </Style>

  <!--
  <Layer name="imagery_layer" srs="+init=epsg:3857">
    <StyleName>aerial_raster_1ft</StyleName>
    <Datasource>
      <Parameter name="type">gdal</Parameter>
      <Parameter name="file">gdal_wms_nm_orthoimagery_1ft.xml</Parameter>
    </Datasource>
  </Layer>
  -->

  <Layer name="streets_layer" srs="+init=epsg:3857">
    <StyleName>basemap</StyleName>
    <Datasource>
      <Parameter name="type">gdal</Parameter>
      <Parameter name="file">gdal_osm_basemap_cache.xml</Parameter>
    </Datasource>
  </Layer>

</Map>