Merge branch 'master' of github.com:melowntech/vts-mapproxy

docs/resources.md

@@ -348,6 +348,33 @@ definition = {
 }
 ```
 
+### Driver: surface-meta
+
+This driver is a special kind of beast. It combines existing surface with TMS to produce internally textured surface.
+It doesn't generate any content on its own but forward all requests to existing surface and TMS resources.
+These drivers must exist in the system.
+
+Caveats/TODO:
+
+* This driver does not support any introspection. If introspection is instroduced in the future it would lack the boundlayer 
+specification (TMS) because this driver already produces its own imagery.
+
+* Also, this driver does not support any other common surface configuration.
+
+* Keeps original surface's credits burned in the metatiles nor `tileset.conf`. In the future, TMS credits (plus any other credits
+configured in this resource) would be included as well.
+
+* So far, during runtime, this driver doesn't watch for changes in the underlying surface/TMS and keeps the old driver
+instance alive while the original resource has been reconfigured and is being served by new driver instance. Restart mapproxy
+if this becomes a problem.
+
+```javascript
+definition = {
+    ResourceId surface                // Resource ID od underlying surface resource
+    ResourceId tms                    // Resource ID od underlying tms resource
+}
+```
+
 ## Geodata drivers
 
 Geodata drivers generate vector geographic data in the form of VTS free layer.