Implement FacetNormals in constraints and Powerconstraints with varying implementation

python/dune/perftool/pdelab/driver/constraints.py

-from dune.perftool.generation import (global_context,
+from dune.perftool.generation import (get_counted_variable,
+                                      global_context,
                                       include_file,
                                       preamble,
                                       )
@@ -52,12 +53,10 @@ def assemble_constraints(name):
 
 
 def name_bctype_function(element, is_dirichlet):
-    if isinstance(element, (VectorElement, TensorElement)):
-        subel = element.sub_elements()[0]
-        child = name_bctype_function(subel, is_dirichlet[:subel.value_size()])
-        name = "{}_pow{}bctype".format(child, element.num_sub_elements())
-        define_power_bctype_function(element, name, child)
-        return name
+    # Note: Previously, there was a separate code branch for VectorElement here,
+    #       which was implemented through PDELabs Power constraints concept.
+    #       However this completely fails if you have different constraints for
+    #       the children of a VectorElement. We therefore omit this branch completely.
     if isinstance(element, MixedElement):
         k = 0
         childs = []
@@ -69,7 +68,7 @@ def name_bctype_function(element, is_dirichlet):
         return name
     else:
         assert isinstance(element, (FiniteElement, TensorProductElement))
-        name = "{}_bctype".format(FEM_name_mangling(element).lower())
+        name = get_counted_variable("bctype")
         define_bctype_function(element, is_dirichlet[0], name)
         return name
 
@@ -85,12 +84,6 @@ def define_bctype_function(element, is_dirichlet, name):
                                                                                        )
 
 
-@preamble(section="constraints")
-def define_power_bctype_function(element, name, subgfs):
-    include_file('dune/pdelab/constraints/common/constraintsparameters.hh', filetag='driver')
-    return "Dune::PDELab::PowerConstraintsParameters<decltype({}), {}> {}({});".format(subgfs, element.num_sub_elements(), name, subgfs)
-
-
 @preamble(section="constraints")
 def define_composite_bctype_function(element, is_dirichlet, name, subgfs):
     include_file('dune/pdelab/constraints/common/constraintsparameters.hh', filetag='driver')

python/dune/perftool/pdelab/driver/visitor.py

@@ -22,6 +22,10 @@ class DriverUFL2PymbolicVisitor(UFL2LoopyVisitor):
         ret = self._call(expr, False)
         return set(self.preambles), ret
 
+    def facet_normal(self, o):
+        self.preambles.append("auto n=is.unitOuterNormal(xl);")
+        return prim.Variable("n")
+
     def spatial_coordinate(self, o):
         self.preambles.append("auto x=is.geometry().global(xl);")
         return prim.Variable("x")