Custom Enchantment adding effect when attacking an Entity

[OwnAgePau]

Hi there,

 

I have been looking into the adding of enchantments and i have gotten my own enchantment "Frost Enchantment" to show up as an enchantment book, to work in an anvil and i have gotten it to be able to get the enchantment from an enchantment table.

 

Now i was looking for the place where minecraft handles the effects of the enchantments. I looked at swords, EntityPlayer, Enchantments and more. But i haven't found much of something that looks like an enchantment effect. All i found was the stuff in EntityPlayer that refers to the EnchantmentHelper. I tired looking at tutorials, although i did find some. Most of them were Modloader tutorials and they were changing base files (which i am not going to do).

 

Where would i add the enchantment effect? would i do that in sword onEntityHit() or whatever that method is called? (i don't have the source in front of my right now)

 

Any help is appreciated, thanks.

[OwnAgePau]

  Quote

I doubt you want to apply the enchantment only to your own sword.

Indeed i don't

 

  Quote

LivingAttackEvent

That sounds like something i want to start looking at thanks a lot. I think i'v got it from here

[OwnAgePau]

I have looked at the event, and i understand what it does. But now i still have no idea where i would call upon this event. Would i do this when i hit an entity? if so in what class would i do that.

[GotoLink]

You don't call an event, unless you want someone else to catch it.

You register to the event, to receive the calls.

[OwnAgePau]

  On 8/10/2013 at 12:49 PM, GotoLink said:

You don't call an event, unless you want someone else to catch it.

You register to the event, to receive the calls.

Oh well, i am sorry that my Englisch isn't my first language and that i happened to have sayd something that wasn't completely what i meant. I meant it more in a way like where would i place the code that would make the effect occur, like i want my enchantment to do an effect whenever it hits an entity, but i couldn't figure out where i would do that.

 

  Quote

Old but still great and up to date: http://www.minecraftforum.net/topic/1419836-forge-4x-events-howto/

I have seen that page indeed, but i still haven't quite gotten straightened out where i would place the effect of my sword. As far as i understand on this thread the guy describes to make a certain class which will use the LivingAttackEvent. So when would this method that is being used in this class be triggered?(called entityAttacked in the example). I understand that i would have to make such a class to hook my "effects" to an event, but i don't yet understand the mechanics behind it. Maybe i am just overthinking this right now (it is quite late for me right now).

[GotoLink]

You can search for

MinecraftForge.EventBus.post(new LivingAttackEvent(args))

or similar.

this is where the event is triggered.

 

If you use PreInit, Init methods and such in your main mod class, you already know how to make a method that can receive an event. The only difference is the event argument, and the @ForgeSubscribe annotation instead of @EventHandler.

Just place this method in a class (you can put in your main class at first) then register with

MinecraftForge.EventBus.register(class);

(you register the entire class, so you can put multiple events in one)

 

You should already have methods ready to read and write an ItemStack NBTTag to get/set your enchantment by the way.

[OwnAgePau]

  On 8/10/2013 at 9:01 PM, GotoLink said:

You should already have methods ready to read and write an ItemStack NBTTag to get/set your enchantment by the way.

Uhm i am not sure if it has anything to do with it, but uhm in EnchantmentHelper there are methods that read and write NBTTag. And my enchantment can already be obtained with crafting books and using an enchantment table. I also discovered that whenever i attack a mob the "magic damage effect" is being shown.

 

Also i haven't done much with forge events and such (still) and i do understand what an event is and all, i just don't yet understand all about the forge related registrations around it. So just to see if i understood you correctly: I will make this method in a custom ForgeHookEvent class (or whatver i will call it) that will take care of the way i handle the effect that will occur whenever i hit a mob. So whenever

  Quote

MinecraftForge.EventBus.post(new LivingAttackEvent(args))

something that code (or similar code) is being run it will execute the entityAttacked(args) method in my ForgeHookEvent.class. Am i right?

 

And yes i do use Init and PreInit

[GotoLink]

Yes, you got it right.

 

  Quote

I also discovered that whenever i attack a mob the "magic damage effect" is being shown.

Wait, so, do you have this effect or not ?

I thought you wanted something to do the effect.

[OwnAgePau]

Well with the magic effet i mean the particles that come off a mob whenever you hit them with an enchantment. But as far as i'm concerned it doesn't give any extra damage. I also wanted to have my frost enchantment do give the entity a slow debuff. (i will post my enchantment code in here as an edit after i have started up my pc)

 

Edit:

package Mod_Ores.Enchantments;

import Mod_Ores.EnumCreatureHelper;
import Mod_Ores.EnumSoulCreatureAttribute;
import net.minecraft.enchantment.Enchantment;
import net.minecraft.enchantment.EnumEnchantmentType;
import net.minecraft.entity.EntityLivingBase;
import net.minecraft.entity.EnumCreatureAttribute;

public class EnchantmentFrost extends Enchantment
{
/**EnchantmentFrost constructor
 * 
 * @param par1id the effectId
 * @param par2weight the weight (rarity something)
 * @param par3enumenchantmenttype the enchantment type
 */
public EnchantmentFrost(int par1id, int par2weight, EnumEnchantmentType par3enumenchantmenttype)
{
	super(par1id, par2weight, par3enumenchantmenttype);
	this.setName("Frost");
}

public String getName()
{
	return name;
}

    /**
     * Calculates de (magic) damage done by the enchantment on a living entity based on level and entity passed.
     */
    public float calcModifierLiving(int par1, EntityLivingBase par2EntityLivingBase)
    {
        return EnumCreatureHelper.getSoulCreatureAttribute() == EnumSoulCreatureAttribute.FROST ? (float)par1 * 2.5F : (float)par1 * 0.0F;
    }
    // I have made a custom Enum in order to give my mobs a certain attribute and if that attribute is a FROST more damage will be done, that was 1 of the 2 ideas. But i am not sure whether its working completely yet as i haven't tested it yet.
    
    /**
     * Returns the minimal value of enchantability needed on the enchantment level passed.
     */
@Override
    public int getMinEnchantability(int par1)
    {
        return 10 + 20 * (par1 - 1);
    }

    /**
     * Returns the maximum value of enchantability nedded on the enchantment level passed.
     */
@Override
    public int getMaxEnchantability(int par1)
    {
        return super.getMinEnchantability(par1) + 50;
    }

    /**
     * Returns the maximum level that the enchantment can have.
     */
@Override
    public int getMaxLevel()
    {
        return 4;
    }
}

[OwnAgePau]

Okay i have done some testing and registered the custom ForgeHookEvent.class. Whenever i now attack an entity it doesn't do anything, i wonder do i have to super.***method do anything in order to continue the usual stuff and just start coding an if() construction in order to find out whether or not the player is attacking with an enchanted sword with Frost on it. Also before i added the event class i tested out my little bit of code to see if the calcModifier stuff was working and it is. So on certain mobs my weapon now does more damage whenver it has my enchantment so i guess i got 1 part working.

 

So what was that you were saying about NBTTag, i have not worked with it as in, created my own function that uses it. Although i have seen some of those methods and have a general idea of how they work.

[GotoLink]

public float calcModifierLiving(int par1, EntityLivingBase par2EntityLivingBase)
    {
        return EnumCreatureHelper.getSoulCreatureAttribute() == EnumSoulCreatureAttribute.FROST ? (float)par1 * 2.5F : (float)par1 * 0.0F;
    }

How does getter work without any argument ?

Do you setSoulCreatureAttribute() somewhere ?

  Quote

Whenever i now attack an entity it doesn't do anything

Be sure not to cancel the event.You don't need a super.x().

  Quote

start coding an if() construction in order to find out whether or not the player is attacking with an enchanted sword with Frost on it.

This is it. The enchantment you will check by reading the NBTTag from the ItemStack of player.getHeldItem().

[OwnAgePau]

  On 8/11/2013 at 1:27 PM, GotoLink said:

public float calcModifierLiving(int par1, EntityLivingBase par2EntityLivingBase)
    {
        return EnumCreatureHelper.getSoulCreatureAttribute() == EnumSoulCreatureAttribute.FROST ? (float)par1 * 2.5F : (float)par1 * 0.0F;
    }

How does getter work without any argument ?

Do you setSoulCreatureAttribute() somewhere ?

  Quote

Whenever i now attack an entity it doesn't do anything

Be sure not to cancel the event.You don't need a super.x().

  Quote

start coding an if() construction in order to find out whether or not the player is attacking with an enchanted sword with Frost on it.

This is it. The enchantment you will check by reading the NBTTag from the ItemStack of player.getHeldItem().

Jeah i changed my custom getCreatureAttribute it now works the way i wanted it to. All that now matters is what to do in the attackEntityEvent, you say that i have to read from NBTTag. Are there some examples that i could start looking at to get an idea of how to do this properly? As i know that enchantment stuff is already stored in NBTTags so i wouldn't have to do that.

 

And btw how can it be that its being canceld then? all i've got in that event is the if(event.isCancable) statement. Would i get rid of that?

[GotoLink]

Don't do setCanceled(true)

 

ItemStack item =  player.getHeldItem();
if(item!=null && item.getItem() instanceof 'CustomSwordClass' && item.hasTagCompound())
{
NBTTagList enchTag = item.getEnchantmentTagList();//use this if you stored your enchantment at "ench" tag in the item
//then do things
}

[OwnAgePau]

So uhm something i wanted to know is, can i just add more args to this attackEntity method? or should it just be the event.

[GotoLink]

I don't think so.

Most useful args are contained by the event arg.

(event.entityLiving, event.cause, event.ammount in your event case)

[OwnAgePau]

just to clear my mind, how would i get player.getHeldItem? would i make a new instance of a player, which seems irrelevant.

[GotoLink]

event.entityLiving is the entity hit.

event.source contains the entity hitting.

 

if(entity instanceof EntityPlayer)
    ((EntityPlayer) entity).getHeldItem();

[OwnAgePau]

Oh jeah obvious , thanks for clearing my mind and helping me to get to know forge events a bit better.

[OwnAgePau]

Uhm... Theres only event.entityLiving and event.entity. I found out that both em are not the player. What should i use instead?

[GotoLink]

if(event.source instance of EntityDamageSource)
{
  Entity entity = ((EntityDamageSource)event.source).getEntity();
  if(entity instanceof EntityPlayer)
    ((EntityPlayer) entity).getHeldItem();
}

[OwnAgePau]

Well uhm the point is, when i type event.cause it doesn't recognise the field. Apperently theres no event.cause.

[GotoLink]

Yeah, it is event.source actually, but I thought you could take a look at the event class. That is where the field are defined. 

[OwnAgePau]

Oh is that what the event.source is, because i have got it set as

DamageSource attackSource = event.source;

And i thought it was the ammount of damage done to the entity, it seems i was mistaken. Well thanks again

[OwnAgePau]

Okay well i have got it so that it can get the enchantmentTagList() and that gives a number of tags. How can i get infromation from those like i would want to know the enchantment name.

[hydroflame]

specific answer: no idea

general answer: you could always look at how vanilla code does it

 

highlight "enchantmentTagList", right-click and click "show call hierarchy". this will show you everywhere in code where this method is called, you can just follor til you find what vanilla code does with it