[WIP] Increase hotbar watcher safety

- Don't write the Icon ID back into game memory anymore
- Add method to calculate what the slot's icon should be
- Swap HTTP and watcher hook over to the new methods

FFXIVPlugin/Game/HotbarWatcher.cs

@@ -27,29 +27,23 @@ private unsafe void OnGameUpdate(Framework framework) {
 
             for (var slotId = 0; slotId < 16; slotId++) {
                 var gameSlot = hotbar->Slot[slotId];
-
-                // while we could put this refresh into the getIcon call instead, that will cause a few headaches:
-                // 1. Any hotbarIcon call that grabs an icon will *also* trigger a refresh call on the next framework tick.
-                // 2. A hidden slot icon updating won't actually trigger an update until the icon refreshes otherwise.
-                //
-                // This will tamper with game memory in a less-than-desirable way, but this should still be relatively safe
-                // as this method (loading from Slot B) is done by the game itself too. This *may* cause a problem with
-                // other plugins though, maybe?
-                if (gameSlot->Icon == 0 && gameSlot->CommandType != HotbarSlotType.Empty) {
-                    gameSlot->LoadIconFromSlotB();
-                }
-
                 var cachedSlot = this._hotbarCache[hotbarId, slotId];
 
+                // ToDo: Maybe performance optimizations here by caching SlotB information instead?
+                //       Would also involve making HotbarController read icon IDs from this cache, which might be
+                //       a good idea anyways. To my knowledge, IconB will *always* change with Icon, so this might be
+                //       the way to go.
+                var calculatedIcon = XIVDeckPlugin.Instance.SigHelper.CalcIconForSlot(gameSlot);
+
                 if (gameSlot->CommandId == cachedSlot.CommandId && 
-                    gameSlot->Icon == cachedSlot.Icon &&
+                    calculatedIcon == cachedSlot.Icon &&
                     gameSlot->CommandType == cachedSlot.CommandType) continue;
-                    
+
                 hotbarUpdated = true;
                 this._hotbarCache[hotbarId, slotId] = new HotBarSlot {
                     CommandId = gameSlot->CommandId,
-                    Icon = gameSlot->Icon,
-                    CommandType = gameSlot->CommandType
+                    Icon = calculatedIcon,
+                    CommandType = gameSlot->CommandType,
                 };
             }
         }

FFXIVPlugin/Game/SigHelper.cs

@@ -7,6 +7,7 @@
 using FFXIVClientStructs.FFXIV.Client.System.Framework;
 using FFXIVClientStructs.FFXIV.Client.System.Memory;
 using FFXIVClientStructs.FFXIV.Client.System.String;
+using FFXIVClientStructs.FFXIV.Client.UI.Misc;
 using XIVDeck.FFXIVPlugin.Game.Structs;
 using XIVDeck.FFXIVPlugin.Server;
 using XIVDeck.FFXIVPlugin.Server.Messages.Outbound;
@@ -31,12 +32,17 @@ private static class Signatures {
         internal const string SanitizeChatString = "E8 ?? ?? ?? ?? EB 0A 48 8D 4C 24 ?? E8 ?? ?? ?? ?? 48 8D 8D";
 
         internal const string IsQuestCompleted = "E8 ?? ?? ?? ?? 41 88 84 2C";
+
+        internal const string RefreshHotbarSlotInfo = "E8 ?? ?? ?? ?? 0F B6 54 24 ?? 8B 44 24 30";
     }
 
     /***** functions *****/
     [Signature(Signatures.SanitizeChatString, Fallibility = Fallibility.Fallible)]
     private readonly delegate* unmanaged<Utf8String*, int, IntPtr, void> _sanitizeChatString = null!;
 
+    [Signature(Signatures.RefreshHotbarSlotInfo, Fallibility = Fallibility.Fallible)]
+    private readonly delegate* unmanaged<out byte, out uint, out ushort, IntPtr, IntPtr, uint> _getSlotInfo = null!;
+
     // UIModule, message, unused, byte
     [Signature(Signatures.SendChatMessage, Fallibility = Fallibility.Fallible)]
     private readonly delegate* unmanaged<IntPtr, IntPtr, IntPtr, byte, void> _processChatBoxEntry = null!;
@@ -112,6 +118,32 @@ internal bool IsQuestCompleted(uint questId) {
         return this._isQuestCompleted((ushort) (questId & 0xFFFF)) != 0;
     }
 
+    internal void CalcBForSlot(HotBarSlot* slot, out HotbarSlotType actionType, out uint actionId) {
+        if (this._getSlotInfo == null) {
+            actionType = slot->IconTypeB;
+            actionId = slot->IconB;
+        }
+
+        var hotbarModule = Framework.Instance()->GetUiModule()->GetRaptureHotbarModule();
+
+        this._getSlotInfo(out var rSlotActionType, out actionId, out _, (IntPtr) hotbarModule, (IntPtr) slot);
+        actionType = (HotbarSlotType) rSlotActionType;
+    }
+
+    internal int CalcIconForSlot(HotBarSlot* slot) {
+        if (this._getSlotInfo == null) {
+            // Fall back and return the slot icon as-is if this signature nulls out.
+            return slot->Icon;
+        }
+
+        if (slot->CommandType == HotbarSlotType.Empty) {
+            return 0;
+        }
+
+        this.CalcBForSlot(slot, out var slotActionType, out var slotActionId);
+        return slot->GetIconIdForSlot(slotActionType, slotActionId);
+    }
+
     private IntPtr DetourGearsetSave(IntPtr a1, IntPtr a2) {
         PluginLog.Debug("Gearset update!");
         var tmp = this.RGM_WriteFileHook!.Original(a1, a2);

FFXIVPlugin/Server/Controllers/HotbarController.cs

@@ -26,7 +26,7 @@ public unsafe SerializableHotbarSlot GetHotbarSlot(int hotbarId, int slotId) {
         }
 
         var hotbarItem = hotbarModule->HotBar[hotbarId]->Slot[slotId];
-        var iconId = hotbarItem->Icon;
+        var iconId = plugin.SigHelper.CalcIconForSlot(hotbarItem);
 
         return new SerializableHotbarSlot {
             HotbarId = hotbarId,