Change _libwarpx.py functions to LibWarpX class methods (#2696)

* Initial attempt at moving function into LibWarpX

* Bugfix - undefined structs in get_particle_theta

This is untested, identified by IDE/visual inspection only

* Unify newlines

* Delete libwarpx.clight (duplicated picmi.py)

See picmi.constants.c

* Change function descriptive comment to docstring

Also remove extra newline in __init__ beginning.

* Replace pywarpx/_libwarpx calls appropriately

* Fix atexit register of finalize function

* Reorder WarpX.py imports for pre-commit

* Use picmi.Simulation.extension = libwarpx alias

This will hopefully preempt user script changes if we restructure things
to allow multiple WarpX runs to be done within a single Python script.

* Fix libwarpx ref in WarpX.getProbLo/getProbHi

* Update get_particle_boundary_buffer doc reference

1 files changed, 6 insertions, 0 deletions

diff --git a/Python/pywarpx/picmi.py b/Python/pywarpx/picmi.py
index cbe01baa6..49aac44dc 100644
--- a/Python/pywarpx/picmi.py
+++ b/Python/pywarpx/picmi.py
@@ -924,6 +924,12 @@ class EmbeddedBoundary(picmistandard.base._ClassWithInit):
 
 
 class Simulation(picmistandard.PICMI_Simulation):
+
+    # Set the C++ WarpX interface (see _libwarpx.LibWarpX) as an extension to
+    # Simulation objects. In the future, LibWarpX objects may actually be owned
+    # by Simulation objects to permit multiple WarpX runs simultaneously.
+    extension = pywarpx.libwarpx
+
     def init(self, kw):
 
         self.current_deposition_algo = kw.pop('warpx_current_deposition_algo', None)