fix: NWBug on Explosion Armor

EXILED/Exiled.Events/Patches/Fixes/FixExplosionArmor.cs

@@ -0,0 +1,114 @@
+// -----------------------------------------------------------------------
+// <copyright file="FixExplosionArmor.cs" company="ExMod Team">
+// Copyright (c) ExMod Team. All rights reserved.
+// Licensed under the CC BY-SA 3.0 license.
+// </copyright>
+// -----------------------------------------------------------------------
+#pragma warning disable SA1402 // File may only contain a single type
+
+namespace Exiled.Events.Patches.Fixes
+{
+    using System;
+    using System.Collections.Generic;
+    using System.Reflection.Emit;
+    using System.Runtime.CompilerServices;
+
+    using Exiled.API.Features.Pools;
+
+    using Footprinting;
+
+    using HarmonyLib;
+
+    using InventorySystem.Items.Armor;
+
+    using PlayerStatsSystem;
+
+    using UnityEngine;
+
+    using static HarmonyLib.AccessTools;
+
+    /// <summary>
+    /// Patches <see cref="ExplosionDamageHandler"/> cttor.
+    /// Fix Explosion damage calculation using Attacker BodyArmor instead of the one from Victim.
+    /// Bug was already reported to NW (https://git.scpslgame.com/northwood-qa/scpsl-bug-reporting/-/work_items/3243).
+    /// </summary>
+    [HarmonyPatch(typeof(ExplosionDamageHandler), MethodType.Constructor, new Type[] { typeof(Footprint), typeof(Vector3), typeof(float), typeof(int), typeof(ExplosionType) })]
+
+    internal class FixExplosionArmor
+    {
+#pragma warning disable SA1600 // Elements should be documented
+        internal static readonly ConditionalWeakTable<ExplosionDamageHandler, StrongBox<int>> Memory = new();
+#pragma warning restore SA1600 // Elements should be documented
+
+        private static IEnumerable<CodeInstruction> Transpiler(IEnumerable<CodeInstruction> instructions)
+        {
+            List<CodeInstruction> newInstructions = ListPool<CodeInstruction>.Pool.Get(instructions);
+
+            // remove the "if (armorPenetration == 0) return;"
+            newInstructions.RemoveRange(0, 5);
+
+            int offset = 1;
+            int index = newInstructions.FindLastIndex(x => x.StoresField(Field(typeof(ExplosionDamageHandler), nameof(ExplosionDamageHandler._serverLogsText)))) + offset;
+
+            newInstructions.InsertRange(index, new List<CodeInstruction>()
+            {
+                // this.Damage = damage;
+                new(OpCodes.Ldarg_0),
+                new(OpCodes.Ldarg_3),
+                new(OpCodes.Callvirt, PropertySetter(typeof(StandardDamageHandler), nameof(StandardDamageHandler.Damage))),
+
+                // FixExplosionArmor.Memory.Add(this, new StrongBox(value))
+                new(OpCodes.Ldsfld, Field(typeof(FixExplosionArmor), nameof(FixExplosionArmor.Memory))),
+                new(OpCodes.Ldarg_0),
+                new(OpCodes.Ldarg_S, 4),
+                new(OpCodes.Newobj, DeclaredConstructor(typeof(StrongBox<int>), new Type[] { typeof(int), }, false)),
+                new(OpCodes.Callvirt, Method(typeof(ConditionalWeakTable<ExplosionDamageHandler, StrongBox<int>>), nameof(ConditionalWeakTable<ExplosionDamageHandler, StrongBox<int>>.Add))),
+            });
+
+            for (int z = 0; z < newInstructions.Count; z++)
+                yield return newInstructions[z];
+
+            ListPool<CodeInstruction>.Pool.Return(newInstructions);
+        }
+    }
+
+    /// <summary>
+    /// Patches <see cref="ExplosionDamageHandler.ApplyDamage"/>.
+    /// Fix Explosion damage calculation using Attacker BodyArmor instead of the one from Victim.
+    /// Bug was already reported to NW (https://git.scpslgame.com/northwood-qa/scpsl-bug-reporting/-/work_items/3243).
+    /// </summary>
+    [HarmonyPatch(typeof(ExplosionDamageHandler), nameof(ExplosionDamageHandler.ApplyDamage))]
+    internal class FixExplosionArmor2
+    {
+#pragma warning disable SA1600 // Elements should be documented
+        internal static float HelperMethod(ExplosionDamageHandler @this, ReferenceHub ply)
+#pragma warning restore SA1600 // Elements should be documented
+        {
+            if (ply.inventory.TryGetBodyArmor(out BodyArmor bodyArmor) && FixExplosionArmor.Memory.TryGetValue(@this, out StrongBox<int> armorPenetration))
+            {
+                return BodyArmorUtils.ProcessDamage(bodyArmor.VestEfficacy, @this.Damage, armorPenetration.Value);
+            }
+
+            return @this.Damage;
+        }
+
+        private static IEnumerable<CodeInstruction> Transpiler(IEnumerable<CodeInstruction> instructions)
+        {
+            List<CodeInstruction> newInstructions = ListPool<CodeInstruction>.Pool.Get(instructions);
+
+            newInstructions.InsertRange(0, new List<CodeInstruction>()
+            {
+                // base.Damage = FixExplosionArmor2.HelperMethod(this, ply);
+                new(OpCodes.Ldarg_0),
+                new(OpCodes.Ldarg_0),
+                new(OpCodes.Ldarg_1),
+                new(OpCodes.Call, Method(typeof(FixExplosionArmor2), nameof(FixExplosionArmor2.HelperMethod))),
+                new(OpCodes.Callvirt, PropertySetter(typeof(StandardDamageHandler), nameof(StandardDamageHandler.Damage))),
+            });
+            for (int z = 0; z < newInstructions.Count; z++)
+                yield return newInstructions[z];
+
+            ListPool<CodeInstruction>.Pool.Return(newInstructions);
+        }
+    }
+}