[forms] Implement dune-assembler boundary intersection interface

The boundary intersection assemblers in `Dune::Fufem::Forms`
no longer hide the intersection assembler behind the
`LocalElement(Matrix|Vector)Assembler` interface but directly
implement the `LocalBoundaryIntersection(Matrix|Vector)Assembler`
interface.

dune/fufem/forms/integratedboundarybilinearform.hh

@@ -60,20 +60,7 @@ namespace Dune::Fufem::Forms {
       patch_(patch)
     {}
 
-    /**
-     * \brief Register local views
-     *
-     * This has to be called once, before using the assembler.
-     * The passed local views must be the same that are used
-     * when calling the assembler for on an element afterwards.
-     */
-    template<class TestLocalView, class AnsatzLocalView>
-    void preprocess(const TestLocalView& testLocalView, const AnsatzLocalView& ansatzLocalView)
-    {
-      cacheManager_.clear();
-      sumLocalOperator_.registerLocalViews(testLocalView.rootLocalView(), ansatzLocalView.rootLocalView());
-      sumLocalOperator_.registerCaches(cacheManager_.prototype());
-    }
+    // Dune::Assembler interface
 
     void bindLocalViews (const TestRootLocalView& testLocalView, const AnsatzRootLocalView& ansatzLocalView)
     {
@@ -83,39 +70,26 @@ namespace Dune::Fufem::Forms {
     }
 
     void bindElement (const Element& element)
-    {}
-
-    template<class LocalMatrix, class TestLocalView, class AnsatzLocalView>
-    void operator()(const Element& element, LocalMatrix& localMatrix, const TestLocalView& testSubspaceLocalView, const AnsatzLocalView& ansatzSubspaceLocalView)
     {
-      assembleElementMatrix(element, localMatrix);
-    }
-
-    template <class LocalMatrix>
-    void assembleElementMatrix (const Element& element, LocalMatrix& localMatrix)
-    {
-      if (not patch_.containsFaceOf(element))
-        return;
-      for(const auto& intersection : intersections(patch_.gridView(), element))
-        if (patch_.contains(intersection))
-          this->operator()(intersection, localMatrix, 0, 0);
+      sumLocalOperator_.bind(element);
     }
 
     template <class LocalPattern>
-    void assembleElementMatrixPattern(const Element& element, LocalPattern& localPattern)
+    void assembleBoundaryIntersectionMatrixPattern(const Intersection& intersection, LocalPattern& localPattern)
     {
       localPattern.addAll();
     }
 
-    template<class LocalMatrix, class TestLocalView, class AnsatzLocalView>
-    void operator()(const Intersection& intersection, LocalMatrix& localMatrix, const TestLocalView& testSubspaceLocalView, const AnsatzLocalView& ansatzSubspaceLocalView)
+    template<class LocalMatrix>
+    void assembleBoundaryIntersectionMatrix(const Intersection& intersection, LocalMatrix& localMatrix)
     {
+      if (not patch_.contains(intersection))
+        return;
+
       auto facet = intersection.indexInInside();
 
       const auto& geometry = intersection.geometry();
 
-      sumLocalOperator_.bind(intersection.inside());
-
       Impl::forEachTupleEntry(sumLocalOperator_.operators(), [&](auto& op) {
         cacheManager_[FacetKey(op.quadratureRuleKey(), facet)].invalidate();
       });
@@ -135,6 +109,32 @@ namespace Dune::Fufem::Forms {
       });
     }
 
+    // Dune::Fufem interface
+
+    /**
+     * \brief Register local views
+     *
+     * This has to be called once, before using the assembler.
+     * The passed local views must be the same that are used
+     * when calling the assembler for on an element afterwards.
+     */
+    template<class TestLocalView, class AnsatzLocalView>
+    void preprocess(const TestLocalView& testLocalView, const AnsatzLocalView& ansatzLocalView)
+    {
+      bindLocalViews(testLocalView, ansatzLocalView);
+    }
+
+    template<class LocalMatrix, class TestLocalView, class AnsatzLocalView>
+    void operator()(const Element& element, LocalMatrix& localMatrix, const TestLocalView& testSubspaceLocalView, const AnsatzLocalView& ansatzSubspaceLocalView)
+    {
+      if (patch_.containsFaceOf(element))
+      {
+        bindElement(element);
+        for(const auto& intersection : intersections(patch_.gridView(), element))
+          assembleBoundaryIntersectionMatrix(intersection, localMatrix);
+      }
+    }
+
     const BilinearOperator& integrandOperator() const
     {
       return sumOperator_;

dune/fufem/forms/integratedboundarylinearform.hh

@@ -59,20 +59,7 @@ namespace Dune::Fufem::Forms {
       patch_(patch)
     {}
 
-    /**
-     * \brief Register local view
-     *
-     * This has to be called once, before using the assembler.
-     * The passed local view must be the same that is used
-     * when calling the assembler for on an element afterwards.
-     */
-    template<class TestLocalView>
-    void preprocess(const TestLocalView& testLocalView)
-    {
-      cacheManager_.clear();
-      sumLocalOperator_.registerLocalViews(testLocalView.rootLocalView());
-      sumLocalOperator_.registerCaches(cacheManager_.prototype());
-    }
+    // Dune::Assembler interface
 
     void bindLocalView (const TestRootLocalView& testLocalView)
     {
@@ -82,39 +69,20 @@ namespace Dune::Fufem::Forms {
     }
 
     void bindElement (const Element& element)
-    {}
-
-    template<class LocalVector, class TestLocalView>
-    void operator()(const Element& element, LocalVector& localVector, const TestLocalView& testSubspaceLocalView)
     {
-      assembleElementVector(element, localVector);
+      sumLocalOperator_.bind(element);
     }
 
     template<class LocalVector>
-    void assembleElementVector (const Element& element, LocalVector& localVector)
+    void assembleBoundaryIntersectionVector(const Intersection& intersection, LocalVector& localVector)
     {
-      if (not patch_.containsFaceOf(element))
+      if (not patch_.contains(intersection))
         return;
-      for(const auto& intersection : intersections(patch_.gridView(), element))
-        if (patch_.contains(intersection))
-          this->operator()(intersection, localVector);
-    }
-
-    template<class LocalVector, class TestLocalView>
-    void operator()(const Intersection& intersection, LocalVector& localVector, const TestLocalView& testSubspaceLocalView)
-    {
-      (*this)(intersection, localVector);
-    }
 
-    template<class LocalVector>
-    void operator()(const Intersection& intersection, LocalVector& localVector)
-    {
       auto facet = intersection.indexInInside();
 
       const auto& geometry = intersection.geometry();
 
-      sumLocalOperator_.bind(intersection.inside());
-
       Impl::forEachTupleEntry(sumLocalOperator_.operators(), [&](auto& op) {
         cacheManager_[FacetKey(op.quadratureRuleKey(), facet)].invalidate();
       });
@@ -134,6 +102,32 @@ namespace Dune::Fufem::Forms {
       });
     }
 
+    // Dune::Fufem interface
+
+    /**
+     * \brief Register local view
+     *
+     * This has to be called once, before using the assembler.
+     * The passed local view must be the same that is used
+     * when calling the assembler for on an element afterwards.
+     */
+    template<class TestLocalView>
+    void preprocess(const TestLocalView& testLocalView)
+    {
+      bindLocalViews(testLocalView);
+    }
+
+    template<class LocalVector, class TestLocalView>
+    void operator()(const Element& element, LocalVector& localVector, const TestLocalView& testSubspaceLocalView)
+    {
+      if (patch_.containsFaceOf(element))
+      {
+        bindElement(element);
+        for(const auto& intersection : intersections(patch_.gridView(), element))
+          assembleBoundaryIntersectionVector(intersection, localVector);
+      }
+    }
+
     const LinearOperator& integrandOperator() const
     {
       return sumOperator_;