igi's research topics

[Avenger]

0x117/0x90 (re enable/disable button) - The resource fields work as an additional matching key. You can have separate reasons for disabling keys that can work independently.

[igi]

0xb5 - Can't use itemtype - i managed to use it for books. Sadly, one needs to modify the .exe (overwrite one byte) to make it work with other itemtypes too.

param1 - string resref to print

param2 - itemtype (if not 0, then goes to /dev/null).

 

And the offset of that 1 byte to change, and the value to change it to is...?

 

 

Local copy updated - thanks Avenger

[Avenger]

Well, here is the code (slightly annotated).

.text:0053073E 018				 mov	 eax, [edx+_effect.param1]
.text:00530741 018				 mov	 [ecx+4], eax
.text:00530744 018				 mov	 ecx, [ebp+var_4]
.text:00530747 018				 mov	 edx, [ebp+pEffect]
.text:0053074A 018				 mov	 eax, [edx+_effect.param2]
.text:0053074D 018				 mov	 [ecx], eax
.text:0053074F 018				 mov	 ecx, [ebp+pEffect]
.text:00530752 018				 cmp	 [ecx+_effect.param2], 0
.text:00530756 018				 jnz	 short loc_53076C
.text:00530758 018				 mov	 edx, [ebp+var_4]
.text:0053075B 018				 push    edx
.text:0053075C 01C				 mov	 ecx, [ebp+pTarget]
.text:0053075F 01C				 add	 ecx, actor.statsCur.noitemtype
.text:00530765 01C				 call    pushDWordOnList
.text:0053076A 018				 jmp	 short loc_53077E
.text:0053076C	 ; ¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦
.text:0053076C
.text:0053076C	 loc_53076C:							 ; CODE XREF: opc_0b5_noitemtype+5Fj
.text:0053076C 018				 mov	 eax, [ebp+var_4]
.text:0053076F 018				 push    eax
.text:00530770 01C				 mov	 ecx, [ebp+pTarget]
.text:00530773 01C				 add	 ecx, actor.statsCur.restrictequipitemtype
.text:00530779 01C				 call    pushDWordOnList
.text:0053077E
.text:0053077E	 loc_53077E:							 ; CODE XREF: opc_0b5_noitemtype+73j
.text:0053077E 018				 mov	 eax, 1
.text:00530783 018				 mov	 esp, ebp
.text:00530785 004				 pop	 ebp
.text:00530786 000				 retn    4
.text:00530786	 opc_0b5_noitemtype endp

 

One can either disable the jump based on param2, near 00530756. Easiest is to make the jump a nop.

Or you can change the statement near 00530773. It should point to the same list as the one at 0053075F.

The second list is ignored, but the first list is supported by the engine.

 

I guess ToBEx can do (or already did) this.

[Avenger]

More precisely, if our offsets are matching (subtract 0x400000 for file offset), the first modification involves zeroing out the 0x14 byte after 0x75:

 

.text:00530750 4D F0 83 79 1C 00 75 14 8B 55 FC 52 8B 4D 08 81