TileEntityStuff

private boolean canSmelt()
    {
        if (this.furnaceItemStacks[0] == null && this.furnaceItemStacks[3] == null && this.furnaceItemStacks[4] == null)
        {
            return false;
        }
        else
        {
            ItemStack itemstack = MaskForgeRecipes.smelting().getSmeltingResult(this.furnaceItemStacks[0], this.furnaceItemStacks[3], this.furnaceItemStacks[4]);//TODO
            if (itemstack == null) return false;
            if (this.furnaceItemStacks[2] == null) return true;
            if (!this.furnaceItemStacks[2].isItemEqual(itemstack)) return false;
            int result = furnaceItemStacks[2].stackSize + itemstack.stackSize;
            return (result <= getInventoryStackLimit() && result <= itemstack.getMaxStackSize());
        }
    }

    /**
     * Turn one item from the furnace source stack into the appropriate smelted item in the furnace result stack
     */
    public void smeltItem()
    {
        if (this.canSmelt())
        {
            ItemStack itemstack = MaskForgeRecipes.smelting().getSmeltingResult(this.furnaceItemStacks[0], this.furnaceItemStacks[3], this.furnaceItemStacks[4]);//TODO

            if (this.furnaceItemStacks[2] == null)
            {
                this.furnaceItemStacks[2] = itemstack.copy();
            }
            else if (this.furnaceItemStacks[2].isItemEqual(itemstack))
            {
                furnaceItemStacks[2].stackSize += itemstack.stackSize;
            }

            --this.furnaceItemStacks[0].stackSize;

            if (this.furnaceItemStacks[0].stackSize <= 0)
            {
                this.furnaceItemStacks[0] = null;
            }

            --this.furnaceItemStacks[3].stackSize;

            if (this.furnaceItemStacks[3].stackSize <= 0)
            {
                this.furnaceItemStacks[3] = null;
            }

            --this.furnaceItemStacks[4].stackSize;

            if (this.furnaceItemStacks[4].stackSize <= 0)
            {
                this.furnaceItemStacks[4] = null;
            }
        }
    }