From: Luca Heltai <luca.heltai@sissa.it>
Date: Thu, 11 Jun 2020 07:59:04 +0000 (+0200)
Subject: New insert_global_particles
X-Git-Tag: v9.3.0-rc1~1390^2~3
X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=47bd20ff2e02f04d0b0f726d6f3018ff1f4fd691;p=dealii.git

New insert_global_particles
---

diff --git a/include/deal.II/particles/particle_handler.h b/include/deal.II/particles/particle_handler.h
index 82b5b0f4f9..3ea665d83c 100644
--- a/include/deal.II/particles/particle_handler.h
+++ b/include/deal.II/particles/particle_handler.h
@@ -307,6 +307,42 @@ namespace Particles
       const std::vector<std::vector<double>> &  properties = {},
       const std::vector<types::particle_index> &ids        = {});
 
+    /**
+     * Insert a number of particles into the collection of particles. This
+     * function takes a list of particles for which we don't know the associated
+     * cell iterator, and distributes them to the correct local particle
+     * collection of a procesor, by unpacking the locations, figuring out where
+     * to send the particles by calling
+     * GridTools::distributed_compute_point_locations(), and sending the
+     * particles to the corresponding process.
+     *
+     * In order to keep track of what mpi process received what particles, a map
+     * from mpi process to IndexSet is returned by the function. This IndexSet
+     * contains the local indices of the particles that were passed to this
+     * function on the calling mpi process, and that falls within the part of
+     * the triangulation owned by this mpi process.
+     *
+     * @param[in] particles A vector of particles that do not need to be on the
+     * local processor
+     *
+     * @param[in] global_bounding_boxes A vector of vectors of bounding boxes.
+     * The bounding boxes `global_bboxes[rk]` describe which part of the mesh is
+     * locally owned by the mpi process with rank `rk`. The local description
+     * can be obtained from GridTools::compute_mesh_predicate_bounding_box(),
+     * and the global one can be obtained by passing the local ones to
+     * Utilities::MPI::all_gather().
+     *
+     * @return A map from owner to IndexSet, that contains the local indices
+     * of the points that were passed to this function on the calling mpi
+     * process, and that falls within the part of triangulation owned by this
+     * mpi process.
+     */
+    std::map<unsigned int, IndexSet>
+    insert_global_particles(
+      const std::vector<Particle<dim, spacedim>> &particles,
+      const std::vector<std::vector<BoundingBox<spacedim>>>
+        &global_bounding_boxes);
+
     /**
      * Set the position of the particles by using the values contained in the
      * vector @p input_vector.
diff --git a/source/particles/particle_handler.cc b/source/particles/particle_handler.cc
index f740e56d03..ad1313d228 100644
--- a/source/particles/particle_handler.cc
+++ b/source/particles/particle_handler.cc
@@ -724,6 +724,43 @@ namespace Particles
 
 
 
+  template <int dim, int spacedim>
+  std::map<unsigned int, IndexSet>
+  ParticleHandler<dim, spacedim>::insert_global_particles(
+    const std::vector<Particle<dim, spacedim>> &particles,
+    const std::vector<std::vector<BoundingBox<spacedim>>>
+      &global_bounding_boxes)
+  {
+    // Store the positions in a vector of points, the ids in a vector of ids,
+    // and the properties, if any, in a vector of vector of properties.
+    std::vector<Point<spacedim>>       positions;
+    std::vector<std::vector<double>>   properties;
+    std::vector<types::particle_index> ids;
+    positions.resize(particles.size());
+    ids.resize(particles.size());
+    if (n_properties_per_particle() > 0)
+      properties.resize(properties.size(),
+                        std::vector<double>(n_properties_per_particle()));
+
+    unsigned int i = 0;
+    for (const auto &p : particles)
+      {
+        positions[i] = p.get_location();
+        ids[i]       = p.get_id();
+        if (p.has_properties())
+          properties[i] = {p.get_properties().begin(),
+                           p.get_properties().end()};
+        ++i;
+      }
+
+    return insert_global_particles(positions,
+                                   global_bounding_boxes,
+                                   properties,
+                                   ids);
+  }
+
+
+
   template <int dim, int spacedim>
   types::particle_index
   ParticleHandler<dim, spacedim>::n_global_particles() const