struct VisStyle
{
	bool			Invert;
	float			Alpha;
	int				RenderStyle;
}

class Inventory : Actor native
{
	const BLINKTHRESHOLD = (4*32);

	native Actor Owner;						// Who owns self item? NULL if it's still a pickup.
	native int Amount;						// Amount of item self instance has
	native int MaxAmount;					// Max amount of item self instance can have
	native int InterHubAmount;				// Amount of item that can be kept between hubs or levels
	native int RespawnTics;					// Tics from pickup time to respawn time
	native TextureID Icon;					// Icon to show on status bar or HUD
	native int DropTime;					// Countdown after dropping
	native Class<Actor> SpawnPointClass;	// For respawning like Heretic's mace
	native Class<Actor> PickupFlash;		// actor to spawn as pickup flash
	native Sound PickupSound;
	native bool bPickupGood;
	native bool bCreateCopyMoved;
	native bool bInitEffectFailed;
	
	Default
	{
		Inventory.Amount 1;
		Inventory.MaxAmount 1;
		Inventory.InterHubAmount 1;
		Inventory.UseSound "misc/invuse";
		Inventory.PickupSound "misc/i_pkup";
		Inventory.PickupMessage "$TXT_DEFAULTPICKUPMSG";
	}
	
	virtual native color GetBlend ();
	virtual native bool HandlePickup(Inventory item);
	virtual native Inventory CreateCopy(Actor other);
	virtual native bool SpecialDropAction (Actor dropper);
	virtual native String PickupMessage();
	virtual native bool ShouldStay();
	virtual native void PlayPickupSound(Actor user);
	
	native bool DoRespawn();
	native bool GoAway();
	native void GoAwayAndDie();
	native void BecomeItem();
	native void BecomePickup();
	
	// In this case the caller function is more than a simple wrapper around the virtual method and
	// is what must be actually called to pick up an item.
	native bool, Actor CallTryPickup(Actor toucher);
	native bool CallStateChain (Actor actor, State state);

	States(Actor, Overlay, Weapon, Item)
	{
	HideDoomish:
		TNT1 A 1050;
		TNT1 A 0 A_RestoreSpecialPosition;
		TNT1 A 1 A_RestoreSpecialDoomThing;
		Stop;
	HideSpecial:
		ACLO E 1400;
		ACLO A 0 A_RestoreSpecialPosition;
		ACLO A 4 A_RestoreSpecialThing1;
		ACLO BABCBCDC 4;
		ACLO D 4 A_RestoreSpecialThing2;
		Stop;
	Held:
		TNT1 A -1;
		Stop;
	HoldAndDestroy:
		TNT1 A 1;
		Stop;
	}
	
	// These are regular functions for the item itself.
	
	//---------------------------------------------------------------------------
	//
	// PROC A_RestoreSpecialThing1
	//
	// Make a special thing visible again.
	//
	//---------------------------------------------------------------------------

	void A_RestoreSpecialThing1()
	{
		bInvisible = false;
		if (DoRespawn ())
		{
			A_PlaySound ("misc/spawn", CHAN_VOICE);
		}
	}

	//---------------------------------------------------------------------------
	//
	// PROC A_RestoreSpecialThing2
	//
	//---------------------------------------------------------------------------

	void A_RestoreSpecialThing2()
	{
		bSpecial = true;
		if (!Default.bNoGravity)
		{
			bNoGravity = false;
		}
		SetState (SpawnState);
	}

	//---------------------------------------------------------------------------
	//
	// PROC A_RestoreSpecialDoomThing
	//
	//---------------------------------------------------------------------------

	void A_RestoreSpecialDoomThing()
	{
		bInvisible = false;
		bSpecial = true;
		if (!Default.bNoGravity)
		{
			bNoGravity = false;
		}
		if (DoRespawn ())
		{
			SetState (SpawnState);
			A_PlaySound ("misc/spawn", CHAN_VOICE);
			Spawn ("ItemFog", Pos, ALLOW_REPLACE);
		}
	}
		

	//===========================================================================
	//
	// AInventory :: CallHandlePickup
	//
	// Runs all HandlePickup methods in the chain
	//
	//===========================================================================

	private bool CallHandlePickup(Inventory item)
	{
		let me = self;
		while (me != null)
		{
			if (me.HandlePickup(item)) return true;
			me = me.Inv;
		}
		return false;
	}
		
	//===========================================================================
	//
	// AInventory :: TryPickup
	//
	//===========================================================================

	virtual protected bool TryPickup (in out Actor toucher)
	{
		Actor newtoucher = toucher; // in case changed by the powerup

		// If HandlePickup() returns true, it will set the IF_PICKUPGOOD flag
		// to indicate that self item has been picked up. If the item cannot be
		// picked up, then it leaves the flag cleared.

		bPickupGood = false;
		if (toucher.Inv != NULL && toucher.Inv.CallHandlePickup (self))
		{
			// Let something else the player is holding intercept the pickup.
			if (!bPickupGood)
			{
				return false;
			}
			bPickupGood = false;
			GoAwayAndDie ();
		}
		else if (MaxAmount > 0)
		{
			// Add the item to the inventory. It is not already there, or HandlePickup
			// would have already taken care of it.
			let copy = CreateCopy (toucher);
			if (copy == NULL)
			{
				return false;
			}
			// Some powerups cannot activate absolutely, for
			// example, PowerMorph; fail the pickup if so.
			if (copy.bInitEffectFailed)
			{
				if (copy != self) copy.Destroy();
				else bInitEffectFailed;
				return false;
			}
			// Handle owner-changing powerups
			if (copy.bCreateCopyMoved)
			{
				newtoucher = copy.Owner;
				copy.Owner = NULL;
				bCreateCopyMoved = false;
			}
			// Continue onwards with the rest
			copy.AttachToOwner (newtoucher);
			if (bAutoActivate)
			{
				if (copy.Use (true))
				{
					if (--copy.Amount <= 0)
					{
						copy.bSpecial = false;
						copy.SetStateLabel ("HoldAndDestroy");
					}
				}
			}
		}
		else if (bAutoActivate)
		{
			// Special case: If an item's MaxAmount is 0, you can still pick it
			// up if it is autoactivate-able.

			// The item is placed in the inventory just long enough to be used.
			toucher.AddInventory(self);
			bool usegood = Use(true);
			toucher.RemoveInventory(self);

			if (usegood)
			{
				GoAwayAndDie();
			}
			else
			{
				return false;
			}
		}
		return true;
	}

	//===========================================================================
	//
	// AInventory :: TryPickupRestricted
	//
	//===========================================================================

	virtual bool TryPickupRestricted (in out Actor toucher)
	{
		return false;
	}

	//===========================================================================
	//
	// AInventory :: AttachToOwner
	//
	//===========================================================================

	virtual void AttachToOwner (Actor other)
	{
		BecomeItem ();
		other.AddInventory (self);
	}

	//===========================================================================
	//
	// AInventory :: DetachFromOwner
	//
	// Performs any special work needed when the item leaves an inventory,
	// either through destruction or becoming a pickup.
	//
	//===========================================================================

	virtual void DetachFromOwner ()
	{
	}

	//===========================================================================
	//
	// AInventory::CreateTossable
	//
	// Creates a copy of the item suitable for dropping. If this actor embodies
	// only one item, then it is tossed out itself. Otherwise, the count drops
	// by one and a new item with an amount of 1 is spawned.
	//
	//===========================================================================

	virtual Inventory CreateTossable ()
	{
		// If self actor lacks a SpawnState, don't drop it. (e.g. A base weapon
		// like the fist can't be dropped because you'll never see it.)
		if (SpawnState == GetDefaultByType("Actor").SpawnState || SpawnState == NULL)
		{
			return NULL;
		}
		if (bUndroppable || bUntossable || Owner == NULL || Amount <= 0)
		{
			return NULL;
		}
		if (Amount == 1 && !bKeepDepleted)
		{
			BecomePickup ();
			DropTime = 30;
			bSpecial = bSolid = false;
			return self;
		}
		let copy = Inventory(Spawn (GetClass(), Owner.Pos, NO_REPLACE));
		if (copy != NULL)
		{
			copy.MaxAmount = MaxAmount;
			copy.Amount = 1;
			copy.DropTime = 30;
			copy.bSpecial = copy.bSolid = false;
			Amount--;
		}
		return copy;
	}

	//===========================================================================
	//
	// AInventory :: DepleteOrDestroy
	//
	// If the item is depleted, just change its amount to 0, otherwise it's destroyed.
	//
	//===========================================================================

	virtual void DepleteOrDestroy ()
	{
		// If it's not ammo or an internal armor, destroy it.
		// Ammo needs to stick around, even when it's zero for the benefit
		// of the weapons that use it and to maintain the maximum ammo
		// amounts a backpack might have given.
		// Armor shouldn't be removed because they only work properly when
		// they are the last items in the inventory.
		if (bKeepDepleted)
		{
			Amount = 0;
		}
		else
		{
			Destroy();
		}
	}

	//===========================================================================
	//
	// AInventory :: Travelled
	//
	// Called when an item in somebody's inventory is carried over to another
	// map, in case it needs to do special reinitialization.
	//
	//===========================================================================

	virtual void Travelled() {}

	//===========================================================================
	//
	// AInventory :: DoEffect
	//
	// Handles any effect an item might apply to its owner
	// Normally only used by subclasses of Powerup
	//
	//===========================================================================

	virtual void DoEffect() {}
	
	
	virtual bool Use (bool pickup) { return false; }
	virtual double GetSpeedFactor() { return 1; }
	virtual bool GetNoTeleportFreeze() { return false; }
	virtual void ModifyDamage(int damage, Name damageType, out int newdamage, bool passive) {}
	virtual void AlterWeaponSprite(VisStyle vis, in out int changed) {}
	virtual void OwnerDied() {}

	//===========================================================================
	//
	// AInventory :: DrawPowerup
	//
	// Gives self item a chance to draw a special status indicator on the screen.
	// Returns false if it didn't draw anything.
	//
	//===========================================================================

	virtual bool DrawPowerup(int x, int y) { return false; }

	//===========================================================================
	//
	// AInventory :: AbsorbDamage
	//
	// Allows inventory items (primarily armor) to reduce the amount of damage
	// taken. Damage is the amount of damage that would be done without armor,
	// and newdamage is the amount that should be done after the armor absorbs
	// it.
	//
	//===========================================================================

	virtual void AbsorbDamage (int damage, Name damageType, out int newdamage) {}
	
}

class DehackedPickup : Inventory native 
{
}

class FakeInventory : Inventory native 
{
	native bool Respawnable;
}