How to use extra_callback_info?

[Andrew350]

So, I'm trying to use the cargo_subtype_display callback to add the word "(optional)" after one of the accepted cargoes for an industry. I have the following code:

Code: Select all

switch (FEAT_INDUSTRIES, SELF, switch_wastelanders_optional_text, extra_callback_info2 & 0x00000001) {
	1: string(STR_WASTELANDERS_OPTIONAL);
	CB_RESULT_NO_TEXT;
}

Honestly, I'm just taking a complete shot in the dark here, but it 'sort of' works. Unfortunately, while it adds the word to the correct cargo, it also adds it to one of the produced cargoes as well, which isn't what I want:

img1.png (57.68 KiB) Viewed 2147 times

I'm pretty sure I'm using extra_callback_info2 wrong, and I really have no idea what to do. Any advice?

Thanks

[PikkaBird]

Why "& 0x00000001"?

[Eddi]

obviously "&0x1" also returns 1 if extra_callback_info2 == 3. to mask the lowest byte, you need to use "&0xFF"

[Andrew350]

Why "& 0x00000001"?

I don't know.

obviously "&0x1" also returns 1 if extra_callback_info2 == 3. to mask the lowest byte, you need to use "&0xFF"

Ok, so I was basically just backwards then, and the lowest byte is actually 0xFF and not 0x01?

(This bit/byte stuff isn't so obvious to some, btw )

[Eddi]

i use the word "obviously" very ironically, obviously

[Andrew350]

Got it Thanks for the help!