source-engine/public/iclientnetworkable.h

//========= Copyright Valve Corporation, All rights reserved. ============//
//
// Purpose: 
//
// $NoKeywords: $
//=============================================================================//

#ifndef ICLIENTNETWORKABLE_H
#define ICLIENTNETWORKABLE_H
#ifdef _WIN32
#pragma once
#endif


#include "iclientunknown.h"
#include "tier1/bitbuf.h"


class IClientEntity;
class ClientClass;


enum ShouldTransmitState_t
{
	SHOULDTRANSMIT_START=0,	// The entity is starting to be transmitted (maybe it entered the PVS).
	
	SHOULDTRANSMIT_END		// Called when the entity isn't being transmitted by the server.
							// This signals a good time to hide the entity until next time
							// the server wants to transmit its state.
};

// NOTE: All of these are commented out; NotifyShouldTransmit actually
// has all these in them. Left it as an enum in case we want to go back though
enum DataUpdateType_t
{
	DATA_UPDATE_CREATED = 0,	// indicates it was created +and+ entered the pvs
//	DATA_UPDATE_ENTERED_PVS,
	DATA_UPDATE_DATATABLE_CHANGED,
//	DATA_UPDATE_LEFT_PVS,
//	DATA_UPDATE_DESTROYED,		// FIXME: Could enable this, but it's a little worrying
								// since it changes a bunch of existing code
};

abstract_class IClientNetworkable
{
public:
	// Gets at the containing class...
	virtual IClientUnknown*	GetIClientUnknown() = 0;

	// Called by the engine when the server deletes the entity.
	virtual void			Release() = 0;

	// Supplied automatically by the IMPLEMENT_CLIENTCLASS macros.
	virtual ClientClass*	GetClientClass() = 0;

	// This tells the entity what the server says for ShouldTransmit on this entity.
	// Note: This used to be EntityEnteredPVS/EntityRemainedInPVS/EntityLeftPVS.
	virtual void			NotifyShouldTransmit( ShouldTransmitState_t state ) = 0;



	//
	// NOTE FOR ENTITY WRITERS: 
	//
	// In 90% of the cases, you should hook OnPreDataChanged/OnDataChanged instead of 
	// PreDataUpdate/PostDataUpdate.
	//
	// The DataChanged events are only called once per frame whereas Pre/PostDataUpdate
	// are called once per packet (and sometimes multiple times per frame).
	//
	// OnDataChanged is called during simulation where entity origins are correct and 
	// attachments can be used. whereas PostDataUpdate is called while parsing packets
	// so attachments and other entity origins may not be valid yet.
	//

	virtual void			OnPreDataChanged( DataUpdateType_t updateType ) = 0;
	virtual void			OnDataChanged( DataUpdateType_t updateType ) = 0;

	// Called when data is being updated across the network.
	// Only low-level entities should need to know about these.
	virtual void			PreDataUpdate( DataUpdateType_t updateType ) = 0;
	virtual void			PostDataUpdate( DataUpdateType_t updateType ) = 0;


	// Objects become dormant on the client if they leave the PVS on the server.
	virtual bool			IsDormant( void ) = 0;

	// Ent Index is the server handle used to reference this entity.
	// If the index is < 0, that indicates the entity is not known to the server
	virtual int				entindex( void ) const = 0;

	// Server to client entity message received
	virtual void			ReceiveMessage( int classID, bf_read &msg ) = 0;

	// Get the base pointer to the networked data that GetClientClass->m_pRecvTable starts at.
	// (This is usually just the "this" pointer).
	virtual void*			GetDataTableBasePtr() = 0;

	// Tells the entity that it's about to be destroyed due to the client receiving
	// an uncompressed update that's caused it to destroy all entities & recreate them.
	virtual void			SetDestroyedOnRecreateEntities( void ) = 0;
};


#endif // ICLIENTNETWORKABLE_H