ptItemData->Flags explained

[kingpin]

I have been looking into how the game knows if an item is Ethereal, Socket, Non-Sellable, Unidentified and other status of an item and here is the result of this.

The game are using a bitsystem to store the info in what is known as flags. In ptItem->ptItemData +18 (Flags) they store this info.

First we can look at the different flags:

ITEMFLAG_NEWITEM = 0x00000001,
ITEMFLAG_TARGETING = 0x00000004,
ITEMFLAG_IS_IDENTIFIED = 0x00000010,
ITEMFLAG_QUANTITY = 0x00000020,
ITEMFLAG_DURABILITY = 0x00000100,
ITEMFLAG_UNKNOWN2 = 0x00000400,
ITEMFLAG_SOCKETED = 0x00000800,
ITEMFLAG_NON_SELLABLE = 0x00001000,
ITEMFLAG_NEWITEM2 = 0x00002000,
ITEMFLAG_UNKNOWN3 = 0x00004000,
ITEMFLAG_CHECKSECPRICE = 0x00010000,
ITEMFLAG_CHECKGAMBLEPRICE = 0x00020000,
ITEMFLAG_UNKNOWN4 = 0x00080000,
ITEMFLAG_ETHERAL = 0x00400000,
ITEMFLAG_UNKNOWN5 = 0x00800000,
ITEMFLAG_FROMPLAYER = 0x01000000,
ITEMFLAG_RUNEWORD = 0x04000000

As we can see here there are several flags that are familar to us like Ethereal, Socketed, Runeword e.tc. Those flags are set/reset and checked all the time when we do anything, or then the game create/delete anything. Then you understand how these flags works, it will help you to change the way item generation are done, like remove all socketed or ethereal items from the game.

As a note: The flag itself just gives information about the item and doesn't make the item ethereal, socket. There are special functions that are called if you want your item to be spawned as ethereal, or with sockets.


D2Common #10707 Check Flags and return a result

Arg1 = ptItem
Arg2 = Flag to check (See the above table what to use)
Arg3 = _LINE_ (Not used any more)
Arg4 = _FILE_ (Not used any more)



With this function above we can check if a flag is set or not. For arg3, I have no idea what it's used for. Have played a bit with different values and doesn't have get any result at all of it. Maybe someone knows what it's used for?


To change the flags we use D2Common.#10708. With this function we can either remove or add a flag.

D2Common.#10708

Arg1 = ptItem
Arg2 = Flag to set/remove (See the above table what to use)
Arg3 = 1 = Set flag, 0 = Remove Flag


There are more functions that are used for test/set/remove flags also, those are D2Common #10709 Test flag, D2Common #10710 Get Flag, D2Common #10711 Set/Remove flag. I havn't looked into those functions yet to se more specific what arguments they use and what difference it is between the other two flags. But, I know these flags are involved with identify process.


The flags on client side plays an important part to choose what to display on the item. I will give an example how they test the flag and display socketed if the item has that flag set.

Code: Select all

6FAE3F7F   68 4C97B76F      PUSH D2Client.6FB7974C           
6FAE3F84   68 C7060000      PUSH 6C7 ; Unknown
6FAE3F89   68 00080000      PUSH 800 ; Socket flag
6FAE3F8E   53               PUSH EBX : ptItem
6FAE3F8F   E8 EA6E0800      CALL <JMP.&D2Common.#10707> : Check flag and return result
6FAE3F94   85C0             TEST EAX,EAX ; test if EAX == 0
6FAE3F96   8B4424 10        MOV EAX,DWORD PTR SS:[ESP+10] 
6FAE3F9A   0F84 A9000000    JE D2Client.6FAE4049 ; Jump if NULL, flag isn't set
6FAE3FA0   85C0             TEST EAX,EAX ; Do test if "," is needed to be added EAX == 0
6FAE3FA2   74 15            JE SHORT D2Client.6FAE3FB9 ; Jump if NULL, no  "," is needed to add 
6FAE3FA4   6A 0F            PUSH 0F
6FAE3FA6   BA 1899B76F      MOV EDX,D2Client.6FB79918                ; ASCII ", "
6FAE3FAB   8D4C24 40        LEA ECX,DWORD PTR SS:[ESP+40]
6FAE3FAF   FFD5             CALL EBP
6FAE3FB1   8D5424 3C        LEA EDX,DWORD PTR SS:[ESP+3C]
6FAE3FB5   8BCE             MOV ECX,ESI
6FAE3FB7   FFD7             CALL EDI
6FAE3FB9   B9 7D0D0000      MOV ECX,0D7D ; Get strinkey for "Socketed: "
6FAE3FBE   E8 157E0800      CALL <JMP.&D2Lang.#10004>

This above is an example how they take advance of the flag system.


We will also look how the game decides if it should create sockets or not on server side then the item are generated.

I don't explain how they do the choose if the item is going to be socketed or not. The code that handles that is above and this code is part of the superior item generation.

Code: Select all

6FC4D7A0   6A 01            PUSH 1 ; Set flag
6FC4D7A2   68 00080000      PUSH 800 ; We will generate socketed item, so the flag needs to be set to socketed.
6FC4D7A7   56               PUSH ESI ; ptItem
6FC4D7A8   E8 29E00C00      CALL <JMP.&D2Common.#10708> ; Set Flag
6FC4D7AD   56               PUSH ESI ; ptItem
6FC4D7AE   E8 C5E30C00      CALL <JMP.&D2Common.#10875> ; Get Version
6FC4D7B3   66:3D 0100       CMP AX,1 ; if classic version ax < 1
6FC4D7B7   72 18            JB SHORT D2Game.6FC4D7D1 ;  then jump
6FC4D7B9   56               PUSH ESI ; ptItem
6FC4D7BA   E8 5FE30C00      CALL <JMP.&D2Common.#10693> ;  Get start Seed
6FC4D7BF   33D2             XOR EDX,EDX ; Make sure EDX is 0
6FC4D7C1   F7F7             DIV EDI ;  The rest of the division is stored in EDX (EAX = EAX/DIV) and we use the rest for decide randomly how many sockets to add
6FC4D7C3   42               INC EDX ; Make sure sockets is never 0
6FC4D7C4   52               PUSH EDX  ;  Number of Sockets
6FC4D7C5   56               PUSH ESI ; ptItem
6FC4D7C6   E8 0DE40C00      CALL <JMP.&D2Common.#10817> ; Set number of sockets

EDIT:
26/11 minor update: renamed UNID to IS_IDENTIFIED

[Myhrginoc]

Another fine job!

I took the liberty of rearranging your table a bit. It looks like there are quite a few more unknown or unused flags. I know you were writing yours in C/C++ format, which this table isn't. I figure we can add to the table as we discover new flags.

Code: Select all

0000 0001 - ITEMFLAG_NEWITEM 
0000 0002 - ?
0000 0004 - ITEMFLAG_TARGETING
0000 0008 - ?
0000 0010 - ITEMFLAG_IS_IDENTIFIED
0000 0020 - ITEMFLAG_QUANTITY
0000 0040 - ?
0000 0080 - ? 
0000 0100 - ITEMFLAG_DURABILITY
0000 0200 - ?
0000 0400 - ? (your unknown2)
0000 0800 - ITEMFLAG_SOCKETED
0000 1000 - ITEMFLAG_NON_SELLABLE
0000 2000 - ITEMFLAG_NEWITEM2
0000 4000 - ? (your unknown3)
0000 8000 - ?
0001 0000 - ITEMFLAG_CHECKSECPRICE
0002 0000 - ITEMFLAG_CHECKGAMBLEPRICE
0004 0000 - ?
0008 0000 - ? (your unknown4)
0010 0000 - ?
0020 0000 - ?
0040 0000 - ITEMFLAG_ETHEREAL
0080 0000 - ? (your unknown5)
0100 0000 - ITEMFLAG_FROMPLAYER
0200 0000 - ?
0400 0000 - ITEMFLAG_RUNEWORD
0800 0000 - ?
1000 0000 - ?
2000 0000 - ?
4000 0000 - ?
8000 0000 - ? (always set for items, do not use)

[kingpin]

I took the liberty of rearranging your table a bit. It looks like there are quite a few more unknown or unused flags. I know you were writing yours in C/C++ format, which this table isn't. I figure we can add to the table as we discover new flags.

Nice, I didn't think to write it in non c++ style

8000 0000 - ? (sign bit, might be invalid to use)

This one is always spawned on an item and you are probably right that we cannot use this one for anything.

EDIT:

Just testing some of the unknown flags.

Flag 00000008 : If this flag is set the game cannot load, you cannot sell the item

Flag 0020 0000 : If this flag it set, it turns a magic item into normal. Maybe another "new" item flag? this one could maybe be compactSave flag? Could also simply be set item to "normal" item

Flag 0200 0000 : Set item as Crude item

[Myhrginoc]

Flag 0020 0000 : If this flag it set, it turns a magic item into normal. Maybe another "new" item flag? this one could maybe be compactSave flag? Could also simply be set item to "normal" item

If this flag is set by custom code, does it wipe out any affixes (especially across a game save/load) or are they hidden? If hidden, do they actually affect a character or is the masking a true masking? This could have some innovative applications if it is a true masking and not a wipeout.

[kingpin]

It removes all affixes, stats from the item. So, my guess this is really the compactSave flag. Since, I can't add anything to it afterwards.

It's no problem to add custom code that "hide" a stat. Just check my cursed feature

[Galbraith]

Since this topic is glued to Resource and Tutorial Listing https://d2mods.info/forum/viewtopic.php?f=8&t=22261 I would like to point new readers to more complete itemFlags dictionary:
https://d2mods.info/forum/viewtopic.php ... 29#p486829
Scroll down a bit to 2nd post, first code block section or use ctrl+F and search for ITEMFLAG
There are also some differences. From what I have checked it seems that ITEMFLAG_BEGINNER = 0x00020000 is more correct decription there. (that is flag set for starter's items which cost 1 gold)