Rename fixdiff boundary condition to reflect.

This is what it actually does, we do not support setting arbitrary
derivative values.

API bump.

1 files changed, 2 insertions, 5 deletions

diff --git a/mg2d_boundary.h b/mg2d_boundary.h
index 12c897f..910249f 100644
--- a/mg2d_boundary.h
+++ b/mg2d_boundary.h
@@ -32,12 +32,9 @@ enum MG2DBCType {
      */
     MG2D_BC_TYPE_FIXVAL,
     /**
-     * The normal derivative of the unkown function is fixed on the boundary.
-     *
-     * TODO: the only supported value of the derivative is currently zero, i.e.
-     * periodic boundary conditions.
+     * The unknown function is mirrored across the boundary
      */
-    MG2D_BC_TYPE_FIXDIFF,
+    MG2D_BC_TYPE_REFLECT,
 };
 
 /**