[solved][1.7.10] Destroying an armor

[scoob27]

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

[crackedEgg]

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.

 

[larsgerrits]

this works for me,

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

The second line will cause a NPE.

[crackedEgg]

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?

[scoob27]

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

[crackedEgg]

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.

[crackedEgg]

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]

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.

[scoob27]

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 ?

[Ernio]

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.

[scoob27]

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

[Ernio]

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:

 

 

 

 

 

[scoob27]

Lol !!!

 

Thank you