"How do I ZScript?"

[Matt]

I think it's a good idea to start a new "How do I..." thread just for ZScript.

My reasoning:

1. More of these threads dedicated to a specific topic is probably not a bad idea. A lot of people's questions get quickly bumped into obscurity because of all the activity on the thread and it's hard to keep the motivation to dig through many unsorted irrelevant posts in the hopes of possibly finding your answer.

2. A lot of ZScript stuff is subject to change, so advice that ends up in that main thread may become obsolete or counterproductive.

3. One problem I've noticed from the documentation/wiki discussion is that the people who know how to do things don't know what it is that other people don't know. A thread with these questions might help show where people need the most help, or which ZScript features are not well known or or understood by the userbase. (Some people's answers might also reveal widespread misconceptions that may need to be further addressed in the documentation.)

3.1. If the same solutions keep coming up we might add them to the "Standard Library" too.


So I'll start:

How do you set up a custom property so that all descendants can define it like so:

Code: Select all

class Custom2:Custom1{
  default{
    customproperty "string";
  }
}

or accessed through something like "Custom2.customproperty"?

EDIT: Since this post the answer to this particular question has been well established in the wiki.

[sonic_HD87]

I have one that always bothers me: ZScript has special keywords referring to the engine (vel, pos...), is there a list containing most, if not, all of them? I always think i'm missing something...

[Graf Zahl]

Those are not special keywords but variables of the class actor. You will find all of them in the internal definition of that class

[sonic_HD87]

Those are not special keywords but variables of the class actor. You will find all of them in the internal definition of that class

Hmmm... And last thing: Some of the engine is "scriptified" so we can make weird stuff without touching the GZDoom sourcecode, so what kind of things is possible to toy with without touching actors, if possible?

[Beed28]

In a mod of mine, I'm wanting the BulletPuff actor to give a flag item to any monster that uses a hitscan attack. But it doesn't seem to work. The monster in question doesn't get the flag item it needs, as checking with the "TargetInv" console command proves. What am I missing?

Code: Select all

Class BulletPuff2 : BulletPuff replaces BulletPuff
{
	Default
	{
		+BLOODLESSIMPACT
		+ALWAYSPUFF
		-ALLOWPARTICLES
	}
	States
	{
	Spawn:
		TNT1 A 0 NoDelay A_GiveToTarget("HitscanFlag", 1);
		Stop;
	}
}

[sonic_HD87]

In a mod of mine, I'm wanting the BulletPuff actor to give a flag item to any monster that uses a hitscan attack. But it doesn't seem to work. The monster in question doesn't get the flag item it needs, as checking with the "TargetInv" console command proves. What am I missing?

Code: Select all

Class BulletPuff2 : BulletPuff replaces BulletPuff
{
	Default
	{
		+BLOODLESSIMPACT
		+ALWAYSPUFF
		-ALLOWPARTICLES
	}
	States
	{
	Spawn:
		TNT1 A 0 NoDelay A_GiveToTarget("HitscanFlag", 1);
		Stop;
	}
}

Maybe i'm wrong here, but BulletPuffs doesn't have a target when they spawn. So, when you give an item to a target, no one will get it.

[Nash]

I have one that always bothers me: ZScript has special keywords referring to the engine (vel, pos...), is there a list containing most, if not, all of them? I always think i'm missing something...

Open gzdoom.pk3, look inside zscript/actor.txt. (Almost) everything you'll have access to is under class Actor.

[sonic_HD87]

I have one that always bothers me: ZScript has special keywords referring to the engine (vel, pos...), is there a list containing most, if not, all of them? I always think i'm missing something...

Open gzdoom.pk3, look inside zscript/actor.txt. (Almost) everything you'll have access to is under class Actor.

Yeah, thanks for that.

But it seems like a not-user-friendly documentation. Should i add those thing on the wiki or the wiki already has it?

[Beed28]

In a mod of mine, I'm wanting the BulletPuff actor to give a flag item to any monster that uses a hitscan attack. But it doesn't seem to work. The monster in question doesn't get the flag item it needs, as checking with the "TargetInv" console command proves. What am I missing?

Code: Select all

Class BulletPuff2 : BulletPuff replaces BulletPuff
{
	Default
	{
		+BLOODLESSIMPACT
		+ALWAYSPUFF
		-ALLOWPARTICLES
	}
	States
	{
	Spawn:
		TNT1 A 0 NoDelay A_GiveToTarget("HitscanFlag", 1);
		Stop;
	}
}

Maybe i'm wrong here, but BulletPuffs doesn't have a target when they spawn. So, when you give an item to a target, no one will get it.

There must be a way somehow. I did manage to edit the hitscan functions themselves, but Graf heavily advised against that. So for my new method, I'm trying to detect whether they're firing a hitscan or not, but I haven't had any luck so far.

[Matt]

+PUFFGETSOWNER

[Beed28]

+PUFFGETSOWNER

I forgot that existed! That did the trick wonderfully!

[Major Cooke]

So I made this suggestion and received this response:

You already have full access to the slope's plane equation, from which all of this can be derived.

Great! So now the big question is, how? I want to roll an actor's flat sprite based on the slope and angle their facing.

[Graf Zahl]

I can't help you with the precise math you need. For that I'd have to get out my old math schoolbook to tell you the exact formulas.

[Major Cooke]

Well, in particular, finding the vertices is what I'm after. I think I can handle the rest, and they're all triangles. What function can I use to find them?

[Ed the Bat]

Going back to this topic...
Would anyone be able to teach me how to make a variant of A_RailAttack that honors autoaim?