update()

public void update()
    {
        boolean flag = this.isBurning();
        boolean flag1 = false;

        if (this.isBurning())
        {
            --this.furnaceBurnTime;
        }

        if (!this.world.isRemote)
        {
            ItemStack itemstack = this.furnaceItemStacks.get(1);

            if (this.isBurning() || !itemstack.isEmpty() && !((ItemStack)this.furnaceItemStacks.get(0)).isEmpty())
            {
                if (!this.isBurning() && this.canSmelt())
                {
                    this.furnaceBurnTime = getItemBurnTime(itemstack);
                    this.currentItemBurnTime = this.furnaceBurnTime;

                    if (this.isBurning())
                    {
                        flag1 = true;

                        if (!itemstack.isEmpty())
                        {
                            Item item = itemstack.getItem();
                            itemstack.shrink(1);

                            if (itemstack.isEmpty())
                            {
                                ItemStack item1 = item.getContainerItem(itemstack);
                                this.furnaceItemStacks.set(1, item1);
                            }
                        }
                    }
                }

                if (this.isBurning() && this.canSmelt())
                {
                    ++this.cookTime;

                    if (this.cookTime == this.totalCookTime)
                    {
                        this.cookTime = 0;
                        this.totalCookTime = this.getCookTime(this.furnaceItemStacks.get(0));
                        this.smeltItem();
                        flag1 = true;
                    }
                }
                else
                {
                    this.cookTime = 0;
                }
            }
            else if (!this.isBurning() && this.cookTime > 0)
            {
                this.cookTime = MathHelper.clamp(this.cookTime - 2, 0, this.totalCookTime);
            }

            if (flag != this.isBurning())
            {
                flag1 = true;
                SilverFurnace.setState(this.isBurning(), this.world, this.pos);
            }
        }

        if (flag1)
        {
            this.markDirty();
        }