Hi everyone,

 

I'm trying to make an armor (chest plate) which destroys itself when the player wears it and goes over a certain distance from the ground.

 

To do so i create a fonction which calculates the distance between the player and the ground (i don't think there is a in-game method() that already exists. Am I right ?)

 

Then I tried to make the chest plate to destroy itself and that is where i got some difficulties. First I look for a method which destroys the armor but didn't find one. Then i tried to use the setDamage method from ItemStack :

 

 

@Override
public void onArmorTick(World world, EntityPlayer player, ItemStack itemStack) 
{
	int distanceToGround = 0;

	if(player.inventory.armorItemInSlot(2) != null)
	{
		if (player.inventory.armorItemInSlot(2).getItem() == ModItems.icarusWings)
		{
			...

			if( distanceToGround > 20)
			{
			        player.inventory.armorItemInSlot(2).setItemDamage(this.getMaxDamage());
			}
		}
	}
}

 

 

So when I tried and got too high the armor got fully damaged (its bar is completely empty) but the armor was still in its slot. I also tried to use this.getMaxDamage()+1 but the result was the same.

 

Then I tried the hard way and replace

 player.inventory.armorItemInSlot(2).setItemDamage(this.getMaxDamage()); 

with

player.inventory.armorInventory[2] = null;

 

It actually worked and the armor disappeared when I went over the limit but when I tried to disconnect and reconnect the armor was back in its slot...

 

I thought that the armor = null was only working in the client side and tried to send a packet to the server (using ByteBufUtils.writeItemStack() with the new value of the slot but I realized it was stupid because the server would only receive "null" and won't know what it refers to. So unless i can send the player with it it won't work. I saw in the ByteBufUtils that there is a method to convert NBTT tag. So if I use a tag to store the player variable and send this tag in that packet with the new value do you think it would work ?

 

But with all that I feel like using a sledgehammer to crack a nut... Is there any ways to do it more easily ?

 

Thank you

this works for me,

player.inventory.armorInventory[2] = (ItemStack) null;
player.inventory.armorInventory[2].stackSize = 0;

 

Although you can destroy normal items with setItemDamage(getMaxDamage() + 1) I don't know if this works with armor.

 

this works for me,

player.inventory.armorInventory[2] = (ItemStack) null;
player.inventory.armorInventory[2].stackSize = 0;

The second line will cause a NPE.

this works for me,

player.inventory.armorInventory[2] = (ItemStack) null;
player.inventory.armorInventory[2].stackSize = 0;

The second line will cause a NPE.

 

I am successfully using this very code in a mod with no NPEs. What would you suggest otherwise?

this works for me,

player.inventory.armorInventory[2] = (ItemStack) null;
player.inventory.armorInventory[2].stackSize = 0;

The second line will cause a NPE.

 

I haven't try it but i also think it would cause a NPE since null is not an itemStack even if you cast it.

 

Well since it worked for crackedEgg I will try it but I am not very hopeful  

 

EDIT : As expected i got a nullPointerExeption... I guess you were lucky somehow

Similar code is used in InventoryPlayer.java in both 1.7.10 and 1.8, that is where I got this from. Sorry if it's not the right way to clear an armor item from the armor inventory. But it does seem to work for me.

larsgerrits is correct. This code causes a silent (at least for me) NPE. It does not crash my game. Sorry for the confusion.

Well, back to the drawing board...

 

EDIT:

THIS code does work without NPE.

player.inventory.armorInventory[2] = (ItemStack) null;

forget setting stacksize to zero. If you find a better way to do this please post back.

larsgerrits is correct. This code causes a silent (at least for me) NPE. It does not crash my game. Sorry for the confusion.

Well, back to the drawing board...

 

EDIT:

THIS code does work without NPE.

player.inventory.armorInventory[2] = (ItemStack) null;

forget setting stacksize to zero. If you find a better way to do this please post back.

That's the simplest way to do that.

Yes and it works but it is only temporary since when I quit the game and reconnect the armor is still in the slot as if it was never destroyed.

 

In fact it looks like it's a little bit more complex. Here it's what happened :

1) My inventory is completely empty. I take one piece of the armor in creative and go back to survival

2) I right-click the armor to equip it so it gets in the armor slot and disappears from the hotter

3) I go over the authorized limit and the armor breaks

4) I fall on the ground but don't take any fall damage (which is strange)

5) I log out and reconnect -> The armor is both in the armor slot and the hot bar as if i've never used it...

 

Do you have an idea of what can cause that ?

I am almost 100% sure your code (armour - break) is run on CLIENT. Anything that edits anything (entities, inventory, itemStacks) should be done always on SERVER. You can use world.isRemote to check sides.

 

Also - use Syso to check if your code is even called.

Thanks Ernio, that was the problem. Everything is working perfectly now.

 

Just a question though : According to your suggestion i add an if(!world.isRemote) statement around my armor = null so that will be executed on the server side but before i did that there was nothing to tell where the code should be executed. In that case shouldn't it been executed on both side and so worked like i wanted ?

 

Anyway thanks

That's why i wrote "Also - use Syso to check if your code is even called.", but since you asked me directly I feel obliged to answer:

 

 

 

 

 

Lol !!!

 

Thank you