allow -2 and -1 zoom

src/c3nav/mapdata/urls.py

@@ -3,8 +3,8 @@ from django.conf.urls import url
 from c3nav.mapdata.views import get_cache_package, map_history, tile, tile_access
 
 urlpatterns = [
-    url(r'^(?P<level>\d+)/(?P<zoom>\d+)/(?P<x>-?\d+)/(?P<y>-?\d+).png$', tile, name='mapdata.tile'),
-    url(r'^(?P<level>\d+)/(?P<zoom>\d+)/(?P<x>-?\d+)/(?P<y>-?\d+)/(?P<access_permissions>\d(-\d)*).png$', tile,
+    url(r'^(?P<level>\d+)/(?P<zoom>-?\d+)/(?P<x>-?\d+)/(?P<y>-?\d+).png$', tile, name='mapdata.tile'),
+    url(r'^(?P<level>\d+)/(?P<zoom>-?\d+)/(?P<x>-?\d+)/(?P<y>-?\d+)/(?P<access_permissions>\d(-\d)*).png$', tile,
         name='mapdata.tile'),
     url(r'^history/(?P<level>\d+)/(?P<mode>base|composite)\.(?P<filetype>png|data)$', map_history,
         name='mapdata.map_history'),

src/c3nav/mapdata/views.py

@@ -55,7 +55,7 @@ def tile(request, level, zoom, x, y, access_permissions=None):
         enforce_tile_secret_auth(request)
 
     zoom = int(zoom)
-    if not (0 <= zoom <= 5):
+    if not (-2 <= zoom <= 5):
         raise Http404
 
     cache_package = CachePackage.open_cached()

src/c3nav/site/static/site/js/c3nav.js

@@ -818,6 +818,8 @@ LevelControl = L.Control.extend({
 
     addLevel: function (id, title) {
         this._tileLayers[id] = L.tileLayer((c3nav.tile_server || '/map/') + String(id) + '/{z}/{x}/{y}.png', {
+            minZoom: -2,
+            maxZoom: 5,
             bounds: L.GeoJSON.coordsToLatLngs(c3nav.bounds)
         });
         var overlay = L.layerGroup();

src/c3nav/tileserver/wsgi.py

@@ -135,7 +135,7 @@ class TileServer:
         level, zoom, x, y = match.groups()
 
         zoom = int(zoom)
-        if not (0 <= zoom <= 5):
+        if not (-2 <= zoom <= 5):
             return self.not_found(start_response, b'zoom out of bounds.')
 
         # do this to be thread safe