Screens.h

#ifndef __SCREEN_MANAGER
#define __SCREEN_MANAGER

#include "Types.h"
#include "ScreenIds.h"

// Each screen in the game comes with a Status flag (what was the last thing the screen was doing), an Initialization
// function (which loads up the screen if necessary), a Handler function which is called while the screen is showing and
// a shutdown function which is called when the screen is getting ready to make another screen active.

typedef struct Screens
{
	UINT32		 (*InitializeScreen)(void);
	UINT32		 (*HandleScreen)(void);
	UINT32		 (*ShutdownScreen)(void);

} Screens;

// These defines are used as flags for each screen state. The only legal transition of states is
// SCR_INACTIVE->SCR_INITIALIZING->SCR_ACTIVE->SCR_SHUTTING_DOWN->SCR_INACTIVE ... Anything else
// will cause the system to yak.

#define SCR_INACTIVE		 0x00
#define SCR_INITIALIZING	 0x01
#define SCR_ACTIVE			0x02
#define SCR_SHUTTING_DOWN	0x04

// This extern is made available to make sure that external modules will have access to the screen information

extern Screens GameScreens[MAX_SCREENS];

// We must include all the following .H files which have prototypes for all the initialization, handler and shutdown
// functions for all the screens. There should be as many includes as there are screens.

#include "jascreens.h"

#endif