Add a command line option to provide additional DLL search paths for …

…Windows (requires Python 3.8+)

openage/__main__.py

@@ -56,6 +56,10 @@ def main(argv=None):
                             help=("upon throwing an exception a debug break is "
                                   "triggered. this will crash openage if no "
                                   "debugger is present"))
+    global_cli.add_argument(
+        "--add-dll-search-path", action='append', dest='dll_paths',
+        help="(Windows only) provide additional DLL search path")
+
     devmodes = global_cli.add_mutually_exclusive_group()
     devmodes.add_argument("--devmode", action="store_true",
                           help="force-enable development mode")

openage/game/main.py

@@ -30,6 +30,13 @@ def main(args, error):
     """
     del error  # unused
 
+    win_dll_path_handles = []
+    import sys
+    if sys.platform == 'win32' and args.dll_paths is not None:
+        import os
+        for addtional_path in args.dll_paths:
+            win_dll_path_handles.append(os.add_dll_directory(addtional_path))
+
     # we have to import stuff inside the function
     # as it depends on generated/compiled code
     from .main_cpp import run_game
@@ -40,6 +47,10 @@ def main(args, error):
     from ..cvar.location import get_config_path
     from ..util.fslike.union import Union
 
+    if sys.platform == 'win32':
+        for handle in win_dll_path_handles:
+            handle.close()
+
     # initialize libopenage
     cpp_interface_setup(args)