[1.12.2] Custom status/potion-like effects not bound to any potions?

[Nikedemos]

As you might expect, I searched far and wide for a current tutorial on implementing custom effects. I also searched for "custom potion effects" here at Modder Support, to no avail - there was one particular thread (the one specifying that it's NOT supposed to be a custom effect, but a custom potion item - the exact opposite of what I want to achieve) that kept showing up multiple times, so I gave that idea up.

 

What I'm trying to do is a custom effect that is not bound to any particular potion - and I definitely do not want any extra potions showing up in Creative. This effect has several levels of intensities that stack up.

 

I have this heavily "@Override"-n ItemFood, let's say FructoseGlucoseBomb. Once eaten (onItemUse), instead of nullifying its ItemStack, the item gets damaged, let's say it's got 8 durability overall. Every "consumption" either applies the SugarRush status effect (if the player is not under it already) or increases the intensity of the effect, based on several factors. Also, depending on the intensity of the SugarRush, it would also cause the player to gain other status effects, on random, with random duration etc, like Speed II, Jump Boost  or... Blindness. You know. Because of diabetes. Sugar's bad for you, kids. TL;DR, a status effect, with stackable amplitude, caused by consuming a damageable food item (that bit is done, works like a charm), not by drinking potions, which also causes other random status effects (vanilla/custom), and that status effect does not register a potion.

 

So it wouldn't be a potion that's calling the effect, it would be an instance of ItemFood or a class that extends it. But I still want full "status effect" functionality, like amplitude, duration, consumables that "heal" it etc.

Unfortunately, I couldn't find any tutorials or open-source mods that do such a thing - you know, a status effect not brought on by a potion, but ItemFood.

 

If you could point me to some resources on the subject, I'd be forever grateful! Thanks!

Edited September 12, 2018 by Nikedemos
two very embarassing typos

[jabelar]

On your food item, in the onEaten() method just call the Entity#applyPotionEffect() method to the entity that ate it.

 

Alternatively, you could create your own effect system by associating a custom Capability with the entity and then in the living update event check the capability and write code for whatever you want it to do.

[Nikedemos]

8 hours ago, jabelar said:

On your food item, in the onEaten() method just call the Entity#applyPotionEffect() method to the entity that ate it.

 

Alternatively, you could create your own effect system by associating a custom Capability with the entity and then in the living update event check the capability and write code for whatever you want it to do.

 

Yes, as I said, that bit is done. You know, applying effect upon eating.

 

What I want to achieve is DEFINING the effect that I want to apply in first place. You know, the argument for applyPotionEffect. Without registering a potion. Sorry if I didn't make myself clear.

Edited September 13, 2018 by Nikedemos
That's a bit of a personal question, don't you think so?

[Animefan8888]

9 minutes ago, Nikedemos said:

What I want to achieve is DEFINING the effect that I want to apply in first place. You know, the argument for applyPotionEffect. Without registering a potion. Sorry if I didn't make myself clear.

You just need to create and register a PotionEffect instance via the Registry Event Register<PotionEffect>

[jabelar]

1 hour ago, Animefan8888 said:

You just need to create and register a PotionEffect instance via the Registry Event Register<PotionEffect>

I'm not sure that is quite correct. There are PotionEffect, PotionType and Potion classes. Both PotionType and Potion can be registered but not PotionEffect (as far as I know). 

 

Background

 

It's a bit confusing because like a lot of things in the Minecraft code there is a duplication of some information across those classes. But looking at the fields and methods each class gives better idea of what each is for:

• Potion just has a bit of information in it but includes the attribute map, some registry stuff, and some booleans like "isBadEffect". The registry contains the instances from the MobEffects class. These instances represent things like "regengeration" but not a specific level of regeneration. But an important thing about Potion class is it has the methods performEffect(), affectEntity() and isReady() which I think need to be overridden.
• PotionEffect actually has a single Potion associated with it, but has some key things like the duration, amplifier, whether it is a splash type, whether to show particles, etc.
• PotionType contains a list of (possibly multiple) PotionEffects. The registry is for specific variants of the PotionEffects. So for example, there is both "regeneration" and "long_regeneration".

 

Anyway, my point is that @Nikedemos says he doesn't want his effect to show up as an actual potion in the creative inventory. I'm not certain but I would guess that the PotionType registry will result in it showing up in the creative inventory.

 

Summary

 

Putting it all together I believe you want to create a custom Potion class that overrides the performEffect(), affectEntity() and isReady() methods. You want to register this.

 

Then you want to create a PotionEffect class that is associated with that Potion. There is no registry for this as they are not singleton instances, instead you will create an instance each time you want to apply it.

 

So basically, the Potion is a registered "singleton" instance and PotionEffect is the actual instance in effect (i.e. duration is tracked within this instance). To apply it you can call PotionEffect#getPotion().applyEffect().

 

I think you probably do not want to create a PotionType or register it, because I think that will cause a potion to show up in the creative tab.

 

Caveat

 

I didn't try the above, but just looked at the code and that are the things that looked like are happening.

 

 

Edited September 13, 2018 by jabelar

[Nikedemos]

1 hour ago, jabelar said:

I'm not sure that is quite correct. There are PotionEffect, PotionType and Potion classes. Both PotionType and Potion can be registered but not PotionEffect (as far as I know). 

@Nikedemos

Thanks for all the insights. Yeah, you might be right, it appears as Potions and their effects go together. I've looked at how other mods implement things, and it seems like potions don't just magically appear in the creative inventory. I'm gonna do some more research on the subject - again, thanks! I just needed pointing in the right direction.