Make FlowParameters::bind work with entities of refined grids

dune/dorie/solver/param_interface.hh

@@ -85,7 +85,7 @@ private:
     void verify_cache () const
     {
         if (not std::get<std::shared_ptr<Parameterization>>(_cache.second)) {
-            DUNE_THROW(Dune::Exception, "No parameterization cached."
+            DUNE_THROW(Dune::Exception, "No parameterization cached. "
                 << "Call 'bind' before accessing the parameterization.");
         }
     }
@@ -123,8 +123,12 @@ public:
     /** \param entity Grid entity (codim 0) to bind to
      */
     template <class Entity>
-    void bind (const Entity& entity) const
+    void bind (Entity entity) const
     {
+        // retrieve index of top father element of chosen entity
+        while(entity.hasFather()) {
+            entity = entity.father();
+        }
         const auto index = _mapper.index(entity);
 
         // done if index is already cached
@@ -134,9 +138,10 @@ public:
             return;
         }
 
+        // otherwise find the index in the stored map and cache the values
         const auto it = _param.find(index);
         if (it == _param.end()) {
-            DUNE_THROW(Dune::Exception, "Could not retrieve parameterization"
+            DUNE_THROW(Dune::Exception, "Could not retrieve parameterization "
                 << "for entity " << index);
         }
         _cache = *it;