How do i use actor pointers? (Or whatever they're called)

XASSASSINX · Post by **XASSASSINX** » Sat Feb 17, 2018 3:53 pm

How do i use actor pointers? I'm talking about these things:

A_Chase(0,0,CHF_NOPLAYACTIVE|CHF_NIGHTMAREFAST)

How do i make them true or false? Or change their values? Trying to make something like this:

Code: Select all

A_Chase(0,0,CHF_NOPLAYACTIVE(TRUE)|CHF_NIGHTMAREFAST)

Won't work! Any help?

Mikk- · Post by **Mikk-** » Sat Feb 17, 2018 3:58 pm

Those are called 'flags' - to use them you simply have them in the arguments like in your first example. They're disabled by default - so you don't need to use them if they're not needed.

XASSASSINX · Post by **XASSASSINX** » Sat Feb 17, 2018 4:57 pm

The symbol in the middle of the 2 flags, it's separate the flag and the setting? so what is the true or false option?

Arctangent · Post by **Arctangent** » Sat Feb 17, 2018 6:07 pm

It separates flags, and only flags as flags don't have settings.

The first example is completely correct; like Mikk said, if you want to turn a flag off, you don't include it at all. So, if you wanted to disable CHF_NIGHTMAREFAST in the first example, you'd replace CHF_NOPLAYACTIVE|CHF_NIGHTMAREFAST with just CHF_NOPLAYACTIVE. Or CHF_NOPLAYACTIVE|CHF_FASTCHASE, in the case that you wanted to both turn off CHF_NIGHTMAREFAST and enable CHF_FASTCHASE.

XASSASSINX · Post by **XASSASSINX** » Sat Feb 17, 2018 6:13 pm

hmmm... last thing, i was trying to make a monster that uses A_Fadeout alot, and according to the wiki, when a monster reaches alpha 0 it get removed. but there is a flag that can remove that. It says that "it's equivalent to using TRUE. to prevent this from occuring, use 0" what does that mean? i put the flag and it removes that? (i'm pretty sure i got the information wrong, so i reccomend checking the A_FadeOut wiki page)

Arctangent · Post by **Arctangent** » Sat Feb 17, 2018 6:23 pm

What it's referring to is that, in previous versions of ZDoom, the flags argument wasn't a flags argument; instead, it was just a boolean that only did what FTF_REMOVE does now.

If you want to know the technical mumbo-jumbo behind it, flags are just integers read in binary rather than in decimal, then special meaning is put to particular places in the binary string. So for example, FTF_REMOVE is ( cutting down the word size to 8-bit instead of the more likely 32-bit or 64-bit as it doesn't really matter here ) equivalent to 00000001 in binary, or 1 in decimal, and FTF_CLAMP is equivalent to 00000010 in binary, or 2 in decimal. Since it's the placement that's important and not the end decimal number, inputting 00000011 ( 3 ), 10000011 ( 131 ), or 01100111 ( 103 ) will all result in FTF_REMOVE and FTF_CLAMP being enabled ... though you really shouldn't type in flags as an integer as it's a lot less readable, and you certainly shouldn't enable more binary places than you need in case more flags are added in the future - else unintended behavior could occur in future versions.

But again, FTF_REMOVE is the equivalent to 00000001, or 1, and in Decorate, true is also equal to 1. So it's very easy to expand a boolean argument into a flags argument while keeping compatibility with old mods, as long as the old functionality is transferred into the flag that represents 00000001. Subsequently, though, you shouldn't use values other than false or true ( or 0 or 1, if you dig it that way ) in boolean arguments, as they might just be converted into a flag argument in future versions and again cause unintended behavior.

ZDoom