Try to fix FreeSlip

lbmpy/advanced_streaming/indexing.py

@@ -88,10 +88,10 @@ class BetweenTimestepsIndexing:
 
         if (f_dir, inverse) in self._trivial_offset_translations:
             offsets = (0, ) * self._dim
-        elif f_dir == 'in':
-            offset_array_symbols = self._offset_array_symbols(f_dir, True)
-            offsets = tuple(sp.IndexedBase(s, shape=(1,))[self.dir_symbol] for s in offset_array_symbols)
-            self._required_offset_arrays.add((f_dir, True))
+        else:
+            offset_array_symbols = self._offset_array_symbols(f_dir, inverse)
+            offsets = tuple(sp.IndexedBase(s, shape=(1,))[index] for s in offset_array_symbols)
+            self._required_offset_arrays.add((f_dir, inverse))
 
         return {'index': translated_index, 'offsets': offsets}
 

lbmpy/boundaries/boundaryconditions.py

@@ -208,24 +208,26 @@ class FreeSlip(LbBoundary):
 
     def get_additional_code_nodes(self, lb_method):
         if self.normal_direction:
-            return [MirroredStencilDirections(self.stencil, self.mirror_axis)]
+            return [MirroredStencilDirections(self.stencil, self.mirror_axis), NeighbourOffsetArrays(lb_method.stencil)]
         else:
-            return []
+            return [NeighbourOffsetArrays(lb_method.stencil)]
 
     def __call__(self, f_out, f_in, dir_symbol, inv_dir, lb_method, index_field):
+        neighbor_offset = NeighbourOffsetArrays.neighbour_offset(dir_symbol, lb_method.stencil)
         if self.normal_direction:
-            normal_direction = self.normal_direction
+            tangential_offset = tuple(offset - normal for offset, normal in zip(neighbor_offset, self.normal_direction))
             mirrored_stencil_symbol = MirroredStencilDirections._mirrored_symbol(self.mirror_axis)
-            mirrored_direction = inv_dir[sp.IndexedBase(mirrored_stencil_symbol, shape=(1,))[dir_symbol]]
+            mirrored_direction = sp.IndexedBase(mirrored_stencil_symbol, shape=(1,))[dir_symbol]
         else:
             normal_direction = list()
             for i, cell_name in zip(range(self.dim), self.additional_data):
                 normal_direction.append(index_field[0](cell_name[0]))
             normal_direction = tuple(normal_direction)
+            tangential_offset = tuple(offset - normal for offset, normal in zip(neighbor_offset, normal_direction))
 
             mirrored_direction = index_field[0]('ref_dir')
 
-        return Assignment(f_in(inv_dir[dir_symbol]), f_in[normal_direction](mirrored_direction))
+        return Assignment(f_in.center(inv_dir[dir_symbol]), f_out[tangential_offset](mirrored_direction))
 
 
 # end class FreeSlip