Reconfigured the collision classes to allow for generalization (#1583)

* Reconfigured the collision classes to allow for generalization
* Added literals to PairWiseCoulombCollision
* Minor cleanup of PairWiseCoulombCollision.cpp, removing query of ndt
* Add boilerplate to CollisionBase class
* Fixed white space in CollisionBase.H

Co-authored-by: Axel Huebl <axel.huebl@plasma.ninja>

1 files changed, 52 insertions, 0 deletions

diff --git a/Source/Particles/Collision/CollisionHandler.cpp b/Source/Particles/Collision/CollisionHandler.cpp
new file mode 100644
index 000000000..588e8d008
--- /dev/null
+++ b/Source/Particles/Collision/CollisionHandler.cpp
@@ -0,0 +1,52 @@
+/* Copyright 2020 David Grote
+ *
+ * This file is part of WarpX.
+ *
+ * License: BSD-3-Clause-LBNL
+ */
+#include "CollisionHandler.H"
+#include "PairWiseCoulombCollision.H"
+#include <AMReX_ParmParse.H>
+
+CollisionHandler::CollisionHandler()
+{
+
+    // Read in collision input
+    amrex::ParmParse pp_collisions("collisions");
+    pp_collisions.queryarr("collision_names", collision_names);
+
+    // Create instances based on the collision type
+    auto const ncollisions = collision_names.size();
+    collision_types.resize(ncollisions);
+    allcollisions.resize(ncollisions);
+    for (int i = 0; i < static_cast<int>(ncollisions); ++i) {
+        amrex::ParmParse pp_collision_name(collision_names[i]);
+
+        // For legacy, pairwisecoulomb is the default
+        std::string type = "pairwisecoulomb";
+
+        pp_collision_name.query("type", type);
+        collision_types[i] = type;
+
+        if (type == "pairwisecoulomb") {
+            allcollisions[i] = std::make_unique<PairWiseCoulombCollision>(collision_names[i]);
+        }
+
+    }
+
+}
+
+/** Perform all collisions
+ *
+ * @param cur_time Current time
+ * @param mypc MultiParticleContainer calling this method
+ *
+ */
+void CollisionHandler::doCollisions ( amrex::Real cur_time, MultiParticleContainer* mypc)
+{
+
+    for (auto& collision : allcollisions) {
+        collision->doCollisions( cur_time, mypc);
+    }
+
+}