Toggable object spawn

[nekostuffing]

Ive seen many mods that have options to toggle certain things to spawn or not, like smoke, bullet casings and other actors, but i haven't figured out how to do this, could someone help me understand how that's done, preferably using acs with decorate.

[R4L]

You can do this with CVars and CVARINFO: https://zdoom.org/wiki/CVARINFO

For an example, say I have a Pistol that spawns a smoke actor named BerettaSmokeSpawn in the fire state. You can define a CVar in a CVARINFO lump like so:

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user bool mymod_disablesmoke = false; //Turn on smoke effects by default

Then in the Fire state, say I had this for code:

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Fire:
	BRTT E 1 A_FireProjectile("BerettaSmokeSpawn",0,0,6,8) //Spawn smoke when firing
	BRTT F 1 A_FireBullets(4,5,-1,6,"BulletPuff",1)
	BRTT GHIJKLGO 1 A_WeaponReady
	Goto Ready

Just add your CVar check before the first line:

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Fire:
	TNT1 A 0 A_JumpIf(GetCVar("mymod_disablesmoke"), 2) //Don't spawn smoke
	BRTT E 1 A_FireProjectile("BerettaSmokeSpawn",0,0,6,8)
	BRTT F 1 A_FireBullets(4,5,-1,6,"BulletPuff",1)
	BRTT GHIJKLGO 1 A_WeaponReady
	Goto Ready

A_JumpIf just evaluates if the CVar is true or false (in this case, false) and jumps/skips over A_FireProjectile to A_FireBullets. For more examples of A_Jump, see here: https://zdoom.org/wiki/A_Jump

[nekostuffing]

You can do this with CVars and CVARINFO

This is exactly what i was looking for, thank you!

[Player701]

NB: CVARs used for controlling object spawns should be marked server, otherwise they can and will break multiplayer games! Even if the object in question is just a decoration, its own behavior (such as calls to random(...) may cause a loss of network consistency due to the RNGs on each client going out of sync with each other. And even if this is avoided, by default any actor being spawned will trigger an RNG that is marked important to network sync, which will also eventually break the game if the actor is not spawned for some of the clients. There is actually a way to avoid triggering it, but I'd strongly advise against it because it looks somewhat like a hack and may eventually change at any time (and still doesn't guraantee stable behavior unless your actor is marked +NOINTERACTION, probably not even then).

[nekostuffing]

NB: CVARs used for controlling object spawns should be marked server

I was using user bool but it wasn't even working in single player, changed it to server bool and now the option for turning the effect on and off works, will using server bool cause problems with multiplayer? im not sure if server int is what you meant.

[Player701]

You can use any type (bool or int) depending on the application. For a simple toggle, bool is sufficient. It's the scope (server vs user) that matters. Server CVARs are always synchronized between players, and only the settings controller (i.e. the player who's hosting the game) can change them.

[nekostuffing]

Alright thanks, appreciate it.

[R4L]

Heh, my bad for suggesting a user CVar. I didn't really think about multiplayer when I suggested it.