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engine/changeframelist.h

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+//========= Copyright Valve Corporation, All rights reserved. ============//
+//
+// Purpose: 
+//
+// $NoKeywords: $
+//=============================================================================//
+
+#ifndef CHANGEFRAMELIST_H
+#define CHANGEFRAMELIST_H
+#ifdef _WIN32
+#pragma once
+#endif
+
+
+#include "bitbuf.h"
+
+
+// This class holds the last tick (from host_tickcount) that each property in 
+// a datatable changed at.
+//
+// It provides fast access to a list of properties that changed within a certain frame range.
+//
+// These are created once per entity per frame. Since usually a very small percentage of an
+// entity's properties actually change each frame, this allows you to get a small set of 
+// properties to delta for each client.
+abstract_class IChangeFrameList
+{
+public:
+	
+	// Call this to delete the object.
+	virtual void	Release() = 0;
+
+	// This just returns the value you passed into AllocChangeFrameList().
+	virtual int		GetNumProps() = 0;
+
+	// Sets the change frames for the specified properties to iFrame.
+	virtual void	SetChangeTick( const int *pPropIndices, int nPropIndices, const int iTick ) = 0;
+
+	// Get a list of all properties with a change frame > iFrame.
+	virtual int		GetPropsChangedAfterTick( int iTick, int *iOutProps, int nMaxOutProps ) = 0;
+
+	virtual IChangeFrameList* Copy() = 0; // return a copy of itself
+
+
+protected:
+	// Use Release to delete these.
+	virtual			~IChangeFrameList() {}
+};				
+
+
+// Call to initialize. Pass in the number of properties this CChangeFrameList will hold.
+// All properties will be initialized to iCurFrame.
+IChangeFrameList* AllocChangeFrameList( int nProperties, int iCurFrame );
+
+
+#endif // CHANGEFRAMELIST_H