物品转存简介

信息

什么是IST

IST是Inventory Slot Transfer的全称。它是旷野之息中利用了物品计数和物品实际数量不同步的Bug。

开发者确保了在一般游戏操作中，这两个变量始终保持同步。但是有些操作会导致一个物品格子被重复删除，导致物品计数比物品实际数量少1，然后重复操作，即可使物品计数越来越少。物品计数与实际物品数的差称为“物品计数差”，或者“转存格”。“转存格”不是实际存在的格子，所以用“物品计数差”更准确。但是“转存格”的叫法使用更广泛，所以在本手册中，我们将用“转存格”一词。生成计数差的操作称为“制作转存格”。

背包结构

游戏中，打开背包界面能看到的物品我们称之为“可视背包”。可视背包由一个双链表组成。背包中所有页面的物品都连在同一个表中。比如，在正常背包顺序下，表中有所有的武器，然后所有的弓，然后所有的箭，以此类推，最后是所有的重要道具。在背包界面的一页物品中，最左上的物品是表里排最靠前的，最右下的物品是最靠后的。然后先连一行的物品，再到下一行。

信息

没有物品的格子称为空格。空格不在背包表中，只是在界面中的显示效果。

The items are also stored at the same time in GameData, which is the game’s flag system. The relevant flags are stored with an array type. For example, PorchItem is a flag that stored an array of 420 strings, each string correspond to one item’s name. Other properties of the items are stored each in a different flag, for example PorchItem_EquipFlag is an array of 420 bools (whether the item is equipped), and PorchItem_Value1 is an array of 420 s32s (the value/durability of the item).

Whenever the Visible Inventory changes, the change is synchronized to GameData. We call this process Sync GameData or simply Sync. The GameData is also what is stored in the save files.

技巧

When mCount is 0, you won’t be able to see the items in the inventory when you open it. This is because the game thinks the inventory is empty since the number of items is 0. However, the items are still there. You can throw a weapon or pick up any item - as long as mCount is no longer 0, you will be able to access the inventory again.

Why is it called IST - The main mechanism

The huge number of glitches that are derived from IST all rely on the core mechanism - transferring slots, which is how the glitch got its name.

This all happens when the inventory is Reload-ed, either when loading a save, or restoring the inventory from a quest that takes away your items (i.e. Trial of the Sword, Stranded on Eventide, or any of the Blight Refights).

When restoring the inventory, the game needs to do 3 things:

  1. Delete all of your current items in Visible Inventory.
  2. Load the data of the inventory to restore into GameData.
    • In case of reloading a save, it is loaded from the save file.
    • In case of quests, it is already stored in GameData.
  3. Add the items in GameData one-by-one into the Visible Inventory.

The magic happens in step 1. Since mCount is less than the actual number of items, the game does not fully delete all the items in inventory. These leftover items will still be there after the reload, effectively being transferred from one save to another.

Derivative Glitches

The following glitches depend on IST. Click on the link for more information about each of them.