From: Daniel Arndt <daniel.arndt@iwr.uni-heidelberg.de>
Date: Wed, 9 Jan 2019 18:18:47 +0000 (+0100)
Subject: Merge pull request #7569 from GivAlz/AddTestGlobalTree
X-Git-Tag: v9.1.0-rc1~455
X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7a6b49b1915700eaf561af8f2dfa385a2bab7c26;p=dealii.git

Merge pull request #7569 from GivAlz/AddTestGlobalTree

Add test and support for non-mpi to GridTools::build_global_tree
---

7a6b49b1915700eaf561af8f2dfa385a2bab7c26
diff --cc source/grid/grid_tools.cc
index 57717e4e48,caa15ded21..e48689f582
--- a/source/grid/grid_tools.cc
+++ b/source/grid/grid_tools.cc
@@@ -5090,15 -5088,18 +5090,17 @@@ namespace GridTool
      MPI_Comm                                  mpi_communicator)
    {
  #ifndef DEAL_II_WITH_MPI
-     (void)local_description;
      (void)mpi_communicator;
-     Assert(false,
-            ExcMessage(
-              "GridTools::build_global_description_tree() requires MPI."));
-     return RTree<std::pair<BoundingBox<spacedim>, unsigned int>>{};
+     // Building a tree with the only boxes available without MPI
+     std::vector<std::pair<BoundingBox<spacedim>, unsigned int>> boxes_index(
+       local_description.size());
+     // Adding to each box the rank of the process owning it
+     for (unsigned int i = 0; i < local_description.size(); ++i)
+       boxes_index[i] = std::make_pair(local_description[i], 0u);
+     return pack_rtree(boxes_index);
  #else
      // Exchanging local bounding boxes
 -    std::vector<std::vector<BoundingBox<spacedim>>> global_bboxes;
 -    global_bboxes =
 +    const std::vector<std::vector<BoundingBox<spacedim>>> global_bboxes =
        Utilities::MPI::all_gather(mpi_communicator, local_description);
  
      // Preparing to flatten the vector