How can I use magical item flag to patch specific (item) files?

[a.greene]

I'm trying to restrict a kensai's ability to use magical items weapons via the following (edited)

COPY_EXISTING_REGEXP "^.+\.itm" override					
  PATCH_IF (SOURCE_SIZE > 0x71) THEN BEGIN					
    READ_LONG 0x64 ex_off
    READ_SHORT 0x68 ex_co
    READ_LONG 0x60 enchantment				
    PATCH_IF enchantment > 0 BEGIN						
      READ_BYTE  0x2f "use"
      WRITE_BYTE 0x2f ("%use%" BOR 0b00000100)					
    END
  END

Would it be possible to use the magical item flag instead of enchantment > 0? If so could someone assist me in re-writing this?

Thank you

Cheers,

a.

Edited May 6, 2023 by a.greene

[jmerry]

Of course it would - and there are plenty of magical items with enchantment level 0. Including some weapons.

The relevant flag group is at 0x18, and "magical" is bit #6.

READ_LONG 0x18 flags
PATCH_IF (flags BAND BIT6) BEGIN
  // Do stuff
END

Basically that.

[a.greene]

@jmerry Thank you, I appreciate your reply

[a.greene]

@jmerry

It appears I did not accurately describe what I wanted to do...

Is it possible to only add the kensai flag to magical weapons, and not to all magical items?

[jmerry]

That calls for another layer of filtering. How to detect a weapon? You can run through all of the item types that are weapons; bows, daggers, maces, and so on. You can scan for whether the item uses a proficiency; that's probably the cleanest. You can check for the presence of "melee" or "ranged" or "launcher" abilities, though that might have false positives.

For the proficiency check, you read the byte at 0x31.

READ_LONG 0x18 flags
READ_BYTE 0x31 prof
PATCH_IF (prof > 88 AND prof < 135) BEGIN // Stats 89 to 134 are the proficiencies
  PATCH_IF (flags BAND BIT6) BEGIN
    // Do stuff
  END
END

That should work.

[a.greene]

@jmerry Thank you!