Improvement in electrostic field solve when using EB & a small refactoring of the Electrostatic solver (#2143)

* refactored parts of the electrostatic solver to allow an outside Poisson solver to be installed

* added callback to install a Poisson solver that can be used instead of the MLMG solver

* added call to the poissonsolver callback if one is installed and updated ElectrostaticSolver.cpp to calculate the electric field directly in amrex if EBs are used

* fixed issue causing ElectrostaticSphereEB test to crash

* fixed the logic for when to call computeE

* added function to allow charge density to be deposited in rho_fp from outside WarpX

* fixed inconsistency between labframe and relativistic electrostatic simulation setup

* fixed typo

* fixed issue that caused ElectrostaticSphere test to fail and removed unnecessary call to multiply E_y by -1 when doing a 2d simulation

* revert edit to error handling string

* changes requested during PR review

* additional change requested during PR review

* fixed typo

* revert unnecessary changes

1 files changed, 4 insertions, 0 deletions

diff --git a/Source/Python/WarpXWrappers.cpp b/Source/Python/WarpXWrappers.cpp
index 24ee25dcf..1450011f9 100644
--- a/Source/Python/WarpXWrappers.cpp
+++ b/Source/Python/WarpXWrappers.cpp
@@ -181,6 +181,10 @@ extern "C"
     {
         warpx_py_beforeEsolve = callback;
     }
+    void warpx_set_callback_py_poissonsolver (WARPX_CALLBACK_PY_FUNC_0 callback)
+    {
+        warpx_py_poissonsolver = callback;
+    }
     void warpx_set_callback_py_afterEsolve (WARPX_CALLBACK_PY_FUNC_0 callback)
     {
         warpx_py_afterEsolve = callback;