From a953febfba522579b338d2c8015e3dcfd6315168 Mon Sep 17 00:00:00 2001
From: Ottermandias <nickroederspam+git1@gmail.com>
Date: Sat, 5 Jul 2025 21:59:20 +0200
Subject: [PATCH] Add support for imc-toggle attributes to accessories, and fix
 up attributes when item swapping models.

---
 Penumbra/Meta/ShapeAttributeManager.cs  | 64 +++++++++++++++++++++++++
 Penumbra/Mods/ItemSwap/EquipmentSwap.cs | 49 ++++++++++++++++++-
 2 files changed, 112 insertions(+), 1 deletion(-)

diff --git a/Penumbra/Meta/ShapeAttributeManager.cs b/Penumbra/Meta/ShapeAttributeManager.cs
index a742806f..16901741 100644
--- a/Penumbra/Meta/ShapeAttributeManager.cs
+++ b/Penumbra/Meta/ShapeAttributeManager.cs
@@ -1,3 +1,4 @@
+using System.Collections.Frozen;
 using OtterGui.Services;
 using Penumbra.Collections;
 using Penumbra.Collections.Cache;
@@ -5,6 +6,8 @@ using Penumbra.GameData.Enums;
 using Penumbra.GameData.Interop;
 using Penumbra.GameData.Structs;
 using Penumbra.Interop.Hooks.PostProcessing;
+using Penumbra.Interop.Structs;
+using Penumbra.Meta.Files;
 using Penumbra.Meta.Manipulations;
 
 namespace Penumbra.Meta;
@@ -58,11 +61,72 @@ public unsafe class ShapeAttributeManager : IRequiredService, IDisposable
             _ids[(int)_modelIndex] = model.GetModelId(_modelIndex);
             CheckShapes(collection.MetaCache!.Shp);
             CheckAttributes(collection.MetaCache!.Atr);
+            if (_modelIndex is <= HumanSlot.LFinger and >= HumanSlot.Ears)
+                AccessoryImcCheck(model);
         }
 
         UpdateDefaultMasks(model, collection.MetaCache!.Shp);
     }
 
+    private void AccessoryImcCheck(Model model)
+    {
+        var imcMask = (ushort)(0x03FF & *(ushort*)(model.Address + 0xAAC + 6 * (int)_modelIndex));
+
+        Span<byte> attr =
+        [
+            (byte)'a',
+            (byte)'t',
+            (byte)'r',
+            (byte)'_',
+            AccessoryByte(_modelIndex),
+            (byte)'v',
+            (byte)'_',
+            (byte)'a',
+            0,
+        ];
+        for (var i = 1; i < 10; ++i)
+        {
+            var flag = (ushort)(1 << i);
+            if ((imcMask & flag) is not 0)
+                continue;
+
+            attr[^2] = (byte)('a' + i);
+
+            foreach (var (attribute, index) in _model->ModelResourceHandle->Attributes)
+            {
+                if (!EqualAttribute(attr, attribute.Value))
+                    continue;
+
+                _model->EnabledAttributeIndexMask &= ~(1u << index);
+                break;
+            }
+        }
+    }
+
+    [MethodImpl(MethodImplOptions.AggressiveOptimization | MethodImplOptions.AggressiveInlining)]
+    private static bool EqualAttribute(Span<byte> needle, byte* haystack)
+    {
+        foreach (var character in needle)
+        {
+            if (*haystack++ != character)
+                return false;
+        }
+
+        return true;
+    }
+
+    private static byte AccessoryByte(HumanSlot slot)
+        => slot switch
+        {
+            HumanSlot.Head    => (byte)'m',
+            HumanSlot.Ears    => (byte)'e',
+            HumanSlot.Neck    => (byte)'n',
+            HumanSlot.Wrists  => (byte)'w',
+            HumanSlot.RFinger => (byte)'r',
+            HumanSlot.LFinger => (byte)'r',
+            _                 => 0,
+        };
+
     private void CheckAttributes(AtrCache attributeCache)
     {
         if (attributeCache.DisabledCount is 0)
diff --git a/Penumbra/Mods/ItemSwap/EquipmentSwap.cs b/Penumbra/Mods/ItemSwap/EquipmentSwap.cs
index 5c67df52..216b5841 100644
--- a/Penumbra/Mods/ItemSwap/EquipmentSwap.cs
+++ b/Penumbra/Mods/ItemSwap/EquipmentSwap.cs
@@ -234,9 +234,56 @@ public static class EquipmentSwap
                 mdl.ChildSwaps.Add(mtrl);
         }
 
+        FixAttributes(mdl, slotFrom, slotTo);
+
         return mdl;
     }
 
+    private static void FixAttributes(FileSwap swap, EquipSlot slotFrom, EquipSlot slotTo)
+    {
+        if (slotFrom == slotTo)
+            return;
+
+        var needle = slotTo switch
+        {
+            EquipSlot.Head                         => "atr_mv_",
+            EquipSlot.Ears                         => "atr_ev_",
+            EquipSlot.Neck                         => "atr_nv_",
+            EquipSlot.Wrists                       => "atr_wv_",
+            EquipSlot.RFinger or EquipSlot.LFinger => "atr_rv_",
+            _                                      => string.Empty,
+        };
+
+        var replacement = slotFrom switch
+        {
+            EquipSlot.Head                         => 'm',
+            EquipSlot.Ears                         => 'e',
+            EquipSlot.Neck                         => 'n',
+            EquipSlot.Wrists                       => 'w',
+            EquipSlot.RFinger or EquipSlot.LFinger => 'r',
+            _                                      => 'm',
+        };
+
+        var attributes = swap.AsMdl()!.Attributes;
+        for (var i = 0; i < attributes.Length; ++i)
+        {
+            if (FixAttribute(ref attributes[i], needle, replacement))
+                swap.DataWasChanged = true;
+        }
+    }
+
+    private static unsafe bool FixAttribute(ref string attribute, string from, char to)
+    {
+        if (!attribute.StartsWith(from) || attribute.Length != from.Length + 1 || attribute[^1] is < 'a' or > 'j')
+            return false;
+
+        Span<char> stack = stackalloc char[attribute.Length];
+        attribute.CopyTo(stack);
+        stack[4]  = to;
+        attribute = new string(stack);
+        return true;
+    }
+
     private static void LookupItem(EquipItem i, out EquipSlot slot, out PrimaryId modelId, out Variant variant)
     {
         slot = i.Type.ToSlot();
@@ -399,7 +446,7 @@ public static class EquipmentSwap
             return null;
 
         var folderTo = GamePaths.Mtrl.GearFolder(slotTo, idTo, variantTo);
-        var pathTo = $"{folderTo}{fileName}";
+        var pathTo   = $"{folderTo}{fileName}";
 
         var folderFrom  = GamePaths.Mtrl.GearFolder(slotFrom, idFrom, variantTo);
         var newFileName = ItemSwap.ReplaceId(fileName, prefix, idTo, idFrom);