Glamourer/Glamourer/Interop/RedrawManager.Weapons.cs

using System;
using System.Runtime.InteropServices;
using Dalamud.Hooking;
using Dalamud.Logging;
using Dalamud.Utility.Signatures;
using FFXIVClientStructs.FFXIV.Client.Game.Character;
using Penumbra.GameData.Enums;
using Penumbra.GameData.Structs;

namespace Glamourer.Interop;

public unsafe partial class RedrawManager
{
    public static readonly int CharacterWeaponOffset = (int)Marshal.OffsetOf<Character>("DrawData");

    public delegate void LoadWeaponDelegate(IntPtr offsetCharacter, uint slot, ulong weapon, byte redrawOnEquality, byte unk2,
        byte skipGameObject,
        byte unk4);

    // Weapons for a specific character are reloaded with this function.
    // The first argument is a pointer to the game object but shifted a bit inside.
    // slot is 0 for main hand, 1 for offhand, 2 for unknown (always called with empty data.
    // weapon argument is the new weapon data.
    // redrawOnEquality controls whether the game does anything if the new weapon is identical to the old one.
    // skipGameObject seems to control whether the new weapons are written to the game object or just influence the draw object. (1 = skip, 0 = change)
    // unk4 seemed to be the same as unk1.
    [Signature("E8 ?? ?? ?? ?? 44 8B 9F", DetourName = nameof(LoadWeaponDetour))]
    private readonly Hook<LoadWeaponDelegate> _loadWeaponHook = null!;

    private void LoadWeaponDetour(IntPtr characterOffset, uint slot, ulong weapon, byte redrawOnEquality, byte unk2, byte skipGameObject,
        byte unk4)
    {
        var oldWeapon = weapon;
        var character = (Actor)(characterOffset - CharacterWeaponOffset);
        try
        {
            var identifier = character.GetIdentifier();
            if (_fixedDesigns.TryGetDesign(identifier, out var save))
            {
                PluginLog.Information($"Loaded weapon from fixed design for {identifier}.");
                weapon = slot switch
                {
                    0 => save.MainHand.Value,
                    1 => save.OffHand.Value,
                    _ => weapon,
                };
            }
            else if (redrawOnEquality == 1 && _currentManipulations.TryGetDesign(identifier, out var save2))
            {
                PluginLog.Information($"Loaded weapon from current design for {identifier}.");
                switch (slot)
                {
                    case 0:
                        save2.Data.MainHand = new CharacterWeapon(weapon);
                        break;
                    case 1:
                        save2.Data.OffHand = new CharacterWeapon(weapon);
                        break;
                }
            }
        }
        catch (Exception e)
        {
            PluginLog.Error($"Error on loading new weapon:\n{e}");
        }

        // First call the regular function.
        _loadWeaponHook.Original(characterOffset, slot, oldWeapon, redrawOnEquality, unk2, skipGameObject, unk4);
        // If something changed the weapon, call it again with the actual change, not forcing redraws and skipping applying it to the game object.
        if (oldWeapon != weapon)
            _loadWeaponHook.Original(characterOffset, slot, weapon, 0 /* redraw */, unk2, 1 /* skip */, unk4);
        // If we're not actively changing the offhand and the game object has no offhand, redraw an empty offhand to fix animation problems.
        else if (slot != 1 && character.OffHand.Value == 0)
            _loadWeaponHook.Original(characterOffset, 1, 0, 1 /* redraw */, unk2, 1 /* skip */, unk4);
    }

    // Load a specific weapon for a character by its data and slot.
    public void LoadWeapon(Actor character, EquipSlot slot, CharacterWeapon weapon)
    {
        switch (slot)
        {
            case EquipSlot.MainHand:
                LoadWeaponDetour(character.Address + CharacterWeaponOffset, 0, weapon.Value, 0, 0, 1, 0);
                return;
            case EquipSlot.OffHand:
                LoadWeaponDetour(character.Address + CharacterWeaponOffset, 1, weapon.Value, 0, 0, 1, 0);
                return;
            case EquipSlot.BothHand:
                LoadWeaponDetour(character.Address + CharacterWeaponOffset, 0, weapon.Value,                0, 0, 1, 0);
                LoadWeaponDetour(character.Address + CharacterWeaponOffset, 1, CharacterWeapon.Empty.Value, 0, 0, 1, 0);
                return;
            // function can also be called with '2', but does not seem to ever be.
        }
    }

    // Load specific Main- and Offhand weapons.
    public void LoadWeapon(Actor character, CharacterWeapon main, CharacterWeapon off)
    {
        LoadWeaponDetour(character.Address + CharacterWeaponOffset, 0, main.Value, 1, 0, 1, 0);
        LoadWeaponDetour(character.Address + CharacterWeaponOffset, 1, off.Value,  1, 0, 1, 0);
    }
}