Add restricted zoom levels to WMTS image layers

mapcache/mapcache_template.xml

@@ -198,22 +198,11 @@
    <tileset name="{{ plat }}_abi_{{ sector }}_l1b_{{ product }}">
       <source>{{ plat }}_abi_{{ sector }}_l1b_{{ product }}</source>
       <cache>disk</cache>
-
-      <!-- grid: the "name" attribute of a preconfigured <grid> 
-         you can also use the following notation to limit the area that will be cached and served to clients:
-         <grid restricted_extent="-10 40 10 50">WGS84</grid>
-         this way is better than using a grid with a limited extent, as in this way the tiles that are already
-         cached are not invalidated should you want to modify the restricted extent in the future. When using
-         the restricted_extent attribute, you should give the corresponding information to the client that will
-         be using the service.
-         you can also limit the zoom levels that are cached/accessible by using the minzoom, maxzoom attributes.
-
-
-         NOTE: when adding a <grid> element, you *MUST* make sure that the source you have selected is able to
-         return images in the grid's srs.
-      -->
-<!--         <grid restricted_extent="-10 40 10 50" minzoom="6" maxzoom="8">WGS84</grid>-->
-         <grid>grid_{{ plat }}_abi_radf</grid>
+      {% if product in zoom_levels %}
+      <grid minzoom="{{ zoom_levels[product][0] }}" maxzoom="{{ zoom_levels[product][1] }}">grid_{{ plat }}_abi_radf</grid>
+      {% else %}
+      <grid>grid_{{ plat }}_abi_radf</grid>
+      {% endif %}
 
       <!-- metadata
          optional metadata tags used for responding to GetCapabilities request.
@@ -257,6 +246,7 @@
         <source>{{ plat }}_abi_basemap</source>
         <cache>disk</cache>
         <grid>grid_{{ plat }}_abi_radf</grid>
+<!--        <grid minzoom="0" maxzoom="4">grid_{{ plat }}_abi_radf</grid>-->
         <metadata>
             <title>CSPP Geo Geo2Grid Web Viewer - {{ PLATFORM_LONG_NAMES[plat] }} ABI</title>
             <abstract>{{ PLATFORM_LONG_NAMES[plat] }} ABI Basemap tiles</abstract>

mapcache/render.py

@@ -55,6 +55,15 @@ IMAGE_FORMATS = defaultdict(lambda: 'rgba')
 #     IMAGE_FORMATS['C{:02d}'.format(i)] = 'gray'
 
 
+ZOOM_LEVELS = defaultdict(lambda: (0, 7))
+for ch_num in [4] + list(range(6, 17)):
+    ZOOM_LEVELS[f"C{ch_num:02d}"] = (0, 5)
+ZOOM_LEVELS["C01"] = (0, 6)
+ZOOM_LEVELS["C03"] = (0, 6)
+ZOOM_LEVELS["C05"] = (0, 6)
+ZOOM_LEVELS["C05"] = (0, 6)
+
+
 def main():
     import argparse
     parser = argparse.ArgumentParser(description="Render mapcache template to complete mapcache config.")
@@ -76,6 +85,7 @@ def main():
         'image_autoexpire': image_autoexpire,
         'basemap_autoexpire': basemap_autoexpire,
         'IMAGE_FORMATS': IMAGE_FORMATS,
+        'zoom_levels': ZOOM_LEVELS,
     }
 
     with open(args.template_fn, 'r') as tmpl_file: