[ZScript] Monster targets non-player Actor (+ Goals)

[Nintolerance]

Long time listener, first time caller.

The next step in my first ZDoom project involves making specific enemies target and attack (or "attack") specific actors.

For one monster with a fire extinguisher, I want them to target & attack "fire" actors. (Currently they'll extinguish a fire if they shoot one by accident, but they don't target & chase fires.)

For another monster that resurrects monsters, I want them to target and "chase" corpses. (Currently they'll resurrect a monster if they stumble into one while chasing the player, but they don't go out of their way.)

The wiki has pointed me towards "thing_hate" and "hate targets," but I can't decipher anything workable from those pages. I don't even know if it's ZScript, and not some other language. So I've come here to beg for help.

At a glance, if I could figure out how to implement it, thing_hate does what I want. "Hate actors wih given TID and attack players when shot." So then I'd assign a TID (somehow) to fire actors and tell the Extinguisher Monster to "hate fires."

Likewise, "hate corpses" is probably too tricky but I can just have corpses spawn an invisible "corpse locator" actor for the Repair Bot to "hate," and have the corpse locator vanish. Right?

EDIT: I've tried searching the forums for "hate" but I haven't found anything relevant, so I gambled on starting a thread.

EDIT EDIT: While I'm here, I guess it'd also be nice to have a way to make monsters not blunder into fires.

[Nintolerance]

UPDATE.

Found some fragments of useful information looking through other threads, specifically here:

viewtopic.php?p=981410#p981410

But then that advice (ignore thing_hate, just change monster target directly) is completely contradicted a couple of posts below...

viewtopic.php?p=981433#p981433


...and I'm still no closer to understanding how you'd implement either of those solutions.

[Nintolerance]

UPDATE 2:

Some helpful folks on the HDest discord server gave me some advice.

The first piece of advice was using the functions A_CheckProximity or CheckProximity. It seems that the flag CPXF_SETTARGET would do almost exactly what I want: cause a monster to change target to a specific instance of an actor if it's within a radius of said instance when the function is checked.

A second user suggested using the "goal" pointer. I haven't been able to find any documentation on the use of a "goal" pointer, just forum threads mentioning that it exists and a "CHASEGOAL" flag mentioned in passing on the ZDoom wiki.

Seems like using ZScript to directly change a "goal" pointer is the modern ZScript equivalent of using the Thing_SetGoal special(?) in ACS, described (on the wiki) as useful to make monsters patrol between defined points on the map.