Add structure for resampling algorithms (#1265)

* First version of resampling structure

* Remove new warnings

* Added Doxygen comments

* Minor modifications

* Add do_resampling() in OneStep_sub1

* Apply suggestions from code review

Co-authored-by: Luca Fedeli <luca.fedeli.88@gmail.com>

* Use mutable in ResamplingTrigger and replace run with operator()

* Apply suggestions from code review

Co-authored-by: MaxThevenet <maxence.thevenet@desy.de>

* Make LevelingThinning operator() final

Co-authored-by: Luca Fedeli <luca.fedeli.88@gmail.com>
Co-authored-by: MaxThevenet <maxence.thevenet@desy.de>

1 files changed, 38 insertions, 0 deletions

diff --git a/Source/Particles/Resampling/ResamplingTrigger.cpp b/Source/Particles/Resampling/ResamplingTrigger.cpp
new file mode 100644
index 000000000..3f0b512cf
--- /dev/null
+++ b/Source/Particles/Resampling/ResamplingTrigger.cpp
@@ -0,0 +1,38 @@
+/* Copyright 2019-2020 Neil Zaim
+ *
+ * This file is part of WarpX.
+ *
+ * License: BSD-3-Clause-LBNL
+ */
+#include "ResamplingTrigger.H"
+#include "WarpX.H"
+
+ResamplingTrigger::ResamplingTrigger ()
+{
+    amrex::ParmParse pprt("resampling_trigger");
+
+    std::string resampling_trigger_int_string = "0";
+    pprt.query("intervals", resampling_trigger_int_string);
+    m_resampling_intervals = IntervalsParser(resampling_trigger_int_string);
+
+    pprt.query("max_avg_ppc", m_max_avg_ppc);
+}
+
+bool ResamplingTrigger::triggered (const int timestep, const amrex::Real global_numparts) const
+{
+    if (!m_initialized) {initialize_global_numcells();};
+
+    const amrex::Real avg_ppc = global_numparts/m_global_numcells;
+    return (m_resampling_intervals.contains(timestep) ||
+            avg_ppc > m_max_avg_ppc);
+}
+
+void ResamplingTrigger::initialize_global_numcells () const
+{
+    auto & warpx = WarpX::GetInstance();
+    for (int lev = 0; lev <= warpx.maxLevel(); lev++)
+    {
+        m_global_numcells +=  warpx.boxArray(lev).numPts();
+    }
+    m_initialized = true;
+}