Scan for nearby enemies in ZScript

[Jarewill]

Hello.

I'm looking for a way to "scan" for nearby enemies in ZScript.
What I mean is that I want to get all monsters within a certain radius and return pointers to them, so I can check their classes and states.
My current idea is to use LineTrace, but it will have troubles with height differences. (Scanning on stairs and such)
I was also looking in the GZDoom's ZScript files, to see how CheckRange did it, but I haven't been able to find anything aside a native function.

I'm still new to ZScript, so I wanted to ask here in case anyone knows how to do it.
Thank you.

While I am here, I wanted to ask something about LineTrace.
Is using many LineTraces going to impact performance a lot?
I haven't noticed anything yet, unlike when I was originally using LineAttack for checks, which spawned a lot of puffs.

[Cherno]

Use a BlockThingsIterator.

Code: Select all

double maxDistance = 512;
for (let i = BlockThingsIterator.Create(self, maxDistance); i.Next();) 
		{
			Actor other = i.thing;
			if (other == self)
			{
				continue;
			}
                         double distance = Distance3D(other);
                        if(distance > maxDistance)
			{
				continue;
			}
                        if(other.bISMONSTER == false)
			{
				continue;
			}
                        console.printf(String.Format("%s (%f)",other.GetClassName(),distance));
                }

[Jarewill]

Thank you Cherno!
This seems to be working how I wanted!

[Cherno]

Note that you have to include the distance check, since the BlockThingsIterator's radius parameter is only used to get the blockmaps blocks to check within that radius; Actor that are farther away than this radius will also be found, so they need to be weeded out with a seperate check versus the actual distance between the calling actor (player, in this case) and the found actor.