From b4b41da1d232a192f023fce3adc07f76cd977e53 Mon Sep 17 00:00:00 2001 From: Wolfgang Bangerth Date: Tue, 17 Jan 2023 15:03:49 -0700 Subject: [PATCH] Add a comment for a recent patch. --- source/grid/grid_reordering.cc | 20 +++++++++++++------- 1 file changed, 13 insertions(+), 7 deletions(-) diff --git a/source/grid/grid_reordering.cc b/source/grid/grid_reordering.cc index 7e37ecd9f1..d61d72ada7 100644 --- a/source/grid/grid_reordering.cc +++ b/source/grid/grid_reordering.cc @@ -32,17 +32,23 @@ DEAL_II_NAMESPACE_OPEN namespace { /** - * A set of functions that - * reorder the data from the - * "current" to the "classic" - * format of vertex numbering of - * cells and faces. These functions - * do the reordering of their - * arguments in-place. + * This file uses a different ordering for the vertices in a hex + * cell than we usually do in deal.II. The different convention used + * here originates in what we believed the ordering to be in UCD + * format, until it was discovered in 2022 that UCD will interpret + * this ordering to correspond to inverted cells -- as a + * consequence, the UCD ordering was fixed, but the current file is + * stuck on the old ordering. */ constexpr std::array local_vertex_numbering{ {0, 1, 5, 4, 2, 3, 7, 6}}; + /** + * Following is a set of functions that reorder the data from the + * "current" to the "classic" format of vertex numbering of cells + * and faces. These functions do the reordering of their arguments + * in-place. + */ void reorder_new_to_old_style(std::vector> &) {} -- 2.39.5