IL2CPP - Shim UnityEngine.Input to fix failing to find the type in some games

src/XUnity.AutoTranslator.Plugin.Core/Il2CppInputProxy.cs

@@ -0,0 +1,87 @@
+#if IL2CPP
+
+using System;
+using System.Reflection;
+using UnityEngine;
+
+namespace XUnity.AutoTranslator.Plugin.Core;
+
+/// <summary>
+/// UnityEngine.Input is usually in UnityEngine or UnityEngine.CoreModule (in which case there is a TypeForwardedTo attribute for it in UnityEngine),
+/// but in newer games it can be in UnityEngine.InputLegacyModule with no type forwarding. In this case it's necessary to load from the legacy assembly manually.
+///
+/// Currently slow relection is used to resolve UnityEngine.Input in both UnityEngine.CoreModule and UnityEngine.InputLegacyModule.
+///
+/// This is a pretty dirty solution, but it is very simple and self-contained so it will suffice for now.
+/// Ideally there would be a full abstraction class that also handles Unity.InputSystem like BepInEx.UnityInput.
+///
+/// TODO: Change all input handling to a local copy of BepInEx.UnityInput whenever it's ported to the master branch
+/// </summary>
+public static class Input
+{
+#pragma warning disable CS1591 // Missing XML comment for publicly visible type or member
+
+ private static Type _inputType;
+ private static Type GetInputType()
+ {
+ _inputType ??= Type.GetType( "UnityEngine.Input, UnityEngine.CoreModule" );
+ _inputType ??= Type.GetType( "UnityEngine.Input, UnityEngine.InputLegacyModule" );
+ return _inputType ?? throw new InvalidOperationException( "Failed to find the UnityEngine.Input type" );
+ }
+
+ private static MethodInfo _getKey;
+ public static bool GetKey( KeyCode key )
+ {
+ _getKey ??= GetInputType().GetMethod( "GetKey", [ typeof( KeyCode ) ] )!;
+ return (bool)_getKey.Invoke( null, [ key ] )!;
+ }
+
+ private static MethodInfo _getKeyDown;
+ public static bool GetKeyDown( KeyCode key )
+ {
+ _getKeyDown ??= GetInputType().GetMethod( "GetKeyDown", [ typeof( KeyCode ) ] )!;
+ return (bool)_getKeyDown.Invoke( null, [ key ] )!;
+ }
+
+ private static MethodInfo _getMouseButton;
+ public static bool GetMouseButton( int button )
+ {
+ _getMouseButton ??= GetInputType().GetMethod( "GetMouseButton", [ typeof( int ) ] )!;
+ return (bool)_getMouseButton.Invoke( null, [ button ] )!;
+ }
+
+ private static MethodInfo _getMouseButtonDown;
+ public static bool GetMouseButtonDown( int button )
+ {
+ _getMouseButtonDown ??= GetInputType().GetMethod( "GetMouseButtonDown", [ typeof( int ) ] )!;
+ return (bool)_getMouseButtonDown.Invoke( null, [ button ] )!;
+ }
+
+ private static MethodInfo _resetInputAxes;
+ public static void ResetInputAxes()
+ {
+ _resetInputAxes ??= GetInputType().GetMethod( "ResetInputAxes", [ ] )!;
+ _resetInputAxes.Invoke( null, [ ] );
+ }
+
+ private static PropertyInfo _mouseScrollDelta;
+ public static Vector2 mouseScrollDelta
+ {
+ get
+ {
+ _mouseScrollDelta ??= GetInputType().GetProperty( "mouseScrollDelta" )!;
+ return (Vector2)_mouseScrollDelta.GetValue( null, null )!;
+ }
+ }
+
+ private static PropertyInfo _mousePosition;
+ public static Vector3 mousePosition
+ {
+ get
+ {
+ _mousePosition ??= GetInputType().GetProperty( "mousePosition" )!;
+ return (Vector3)_mousePosition.GetValue( null, null )!;
+ }
+ }
+}
+#endif