Valheim.JoystickFix/JoystickTriggerFix/Plugin.cs

using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Reflection.Emit;
using BepInEx;
using BepInEx.Logging;
using HarmonyLib;

namespace JoystickTriggerFix
{
    [BepInPlugin(PluginInfo.PLUGIN_ID, PluginInfo.PLUGIN_NAME, PluginInfo.PLUGIN_VERSION)]
    public class Plugin : BaseUnityPlugin
    {
        internal static ManualLogSource log;
        
        private void Awake()
        {
            log = Logger;
            Harmony.CreateAndPatchAll(typeof(Plugin));
        }

        [HarmonyPatch(typeof(ZInput), "AddButton", typeof(string), typeof(string), typeof(bool), typeof(float), typeof(float))]
        [HarmonyPrefix]
        static void OnAddButton(ref string axis, ref bool inverted)
        {
            if (axis == "JoyAxis 10")
                axis = "JoyAxis 3";
            if (axis != "JoyAxis 3")
                return;
            log.LogInfo($"Inverting {axis}");
            inverted = !inverted;
        }

        [HarmonyPatch(typeof(ZInput), "GetJoyRTrigger")]
        [HarmonyTranspiler]
        static IEnumerable<CodeInstruction> InvertGetJoyRTrigger(IEnumerable<CodeInstruction> instrs)
        {
            return new CodeMatcher(instrs)
                .MatchForward(false,
                    new CodeMatch(OpCodes.Ldstr))
                .SetOperandAndAdvance("JoyAxis 3")
                .InstructionEnumeration();
        }
        
        [HarmonyPatch(typeof(ZInput), "GetJoyLTrigger")]
        [HarmonyTranspiler]
        static IEnumerable<CodeInstruction> InvertGetJoyLTrigger(IEnumerable<CodeInstruction> instrs)
        {
            return new CodeMatcher(instrs)
                .MatchForward(false,
                    new CodeMatch(OpCodes.Ldstr))
                .SetOperandAndAdvance("JoyAxis 6")
                .InstructionEnumeration();
        }
    }
}