Initialize SDL joystick subsystems lazily

Should fix performance issues caused by calling functions such as
get_controller every frame.

CHANGELOG.md

@@ -6,6 +6,7 @@ This project adheres to [Semantic Versioning](https://semver.org/) since version
 ## [Unreleased]
 ### Fixed
 - Ignore the locale when encoding file paths outside of Windows.
+- Fix performance when calling joystick functions.
 
 ## [16.2.1] - 2023-09-24
 ### Fixed

tcod/sdl/joystick.py

@@ -363,7 +363,10 @@ def _touchpad(self) -> bool:
 
 def init() -> None:
     """Initialize SDL's joystick and game controller subsystems."""
-    tcod.sdl.sys.init(tcod.sdl.sys.Subsystem.JOYSTICK | tcod.sdl.sys.Subsystem.GAMECONTROLLER)
+    CONTROLLER_SYSTEMS = tcod.sdl.sys.Subsystem.JOYSTICK | tcod.sdl.sys.Subsystem.GAMECONTROLLER
+    if tcod.sdl.sys.Subsystem(lib.SDL_WasInit(CONTROLLER_SYSTEMS)) == CONTROLLER_SYSTEMS:
+        return  # Already initialized
+    tcod.sdl.sys.init(CONTROLLER_SYSTEMS)
 
 
 def _get_number() -> int: