Huh, that's weird. ItemStack oddity

[Draco18s 2416]

So I was altering how one of my blocks creates items, changing it from dropping the ore to dropping the dust.  Previously everything worked fine, but in this change, the item stacks it would push into the world were somehow getting a stack size of 0 (no matter how many of them went into the world, the player would only pick up 1 and the ItemEntity itself would look like a larger stack for a short while before "collapsing" to be a stack of 1).

 

Here's the code

 

OreDataHooks.subOreData(worldObj, xCoord+bestj*24, yCoord, zCoord+bestk*24, b, 16);
System.out.println("Found " + b.getUnlocalizedName());
ItemStack is = new ItemStack(b.getItemDropped(0, this.rand, 0), 1, b.damageDropped(0)); //gets the ore chunk from my ore block
System.out.println(is + " " + is.getDisplayName() + ":" + is.stackSize);
if(is.getItem() != Items.redstone && is.getItemDamage() != 2) { //if its one of the ones that can be ground into dust
is = RecipeManager.getMillResult(is); //grind it (makes a stack of 2)
is.stackSize = 1; //make the stack size 1
System.out.println(is + " " + is.getItem() + ":" + is.stackSize);
}
mergeStacks(is);

 

Here's what the printlns print out:

 

1xitem.redstone@0 Redstone:1
1xitem.null@1 Raw Gold Ore:1
1xitem.null@1 com.draco18s.ores.item.ItemOreDustSmall@efad89:1

 

What caught my eye was "1xitem.null" part.  Huh?  They're all registered properly and list their sub items.

 

And why do the dusts end up as a (nearly) empty stack, but the ores don't?

[diesieben07 7705]

1) Your code does not match up with the output (there is no "Found: " text in the output)

2) The "item.null" happens if you don't set the unlocalized name.

[Draco18s 2416]

1) Your code does not match up with the output (there is no "Found: " text in the output)

2) The "item.null" happens if you don't set the unlocalized name.

 

1) Oh, sorry, I clipped that line.  I'd been meaning to only include the relavent bits when I did that copy/paste and forgot to remove the extra out line.  Here's a bunch:

Found tile.ore_gold
1xitem.null@1 Raw Gold Ore:1
1xitem.null@1 com.draco18s.ores.item.ItemOreDustSmall@efad89:1
Found tile.ore_redstone
1xitem.redstone@0 Redstone:1
Found tile.ore_gold
1xitem.null@1 Raw Gold Ore:1
1xitem.null@1 com.draco18s.ores.item.ItemOreDustSmall@efad89:1

2) Ah.  I override getUnlocalizedName, due to the subItems all needing different names.  That makes sense.

 

Any thoughts on why the item entities have an apparent size of 0?

Here's the mergeStack function, which is responsible:

private void mergeStacks(ItemStack stack) {
	if(worldObj.isRemote) return;

	float rx = 0.5F;
	float ry = rand.nextFloat() * 0.25F + 0.25F;
	float rz = 0.5F;

	EntityItem entityItem = new EntityItem(worldObj,xCoord + rx, yCoord + ry, zCoord + rz,stack);

	float factor = 0.05F;
	entityItem.motionX = 0;
	entityItem.motionY = 0;
	entityItem.motionZ = 0;
	entityItem.delayBeforeCanPickup = 10;
	worldObj.spawnEntityInWorld(entityItem);
}

[diesieben07 7705]

Does the RecipeManager clone the ItemStack before returning it? If not, picking up the EntityItem will modify the ItemStack in the RecipeManager's data structure.

[Draco18s 2416]

D'oh.  That's exactly the problem.  (And neither should it!  I should be cloning the result here).

Ah, the limits of human RAM: we can only hold seven objects in memory at once.  I'd forgotten that I'd need to do that.

 

(I do love the implications of not cloning it though: the item exists in multiple places at the same time.  \o/ And physicists tell us that's not possible. )