// Filename 		: VSYNC.C
// Coded by 		: Scott Evans
// Created/Modified : 23/2/98
// Description		: Vertical blank timer routine


#include <vsync.h>


// Timer variable

volatile u_long timer;


// Function			: InstallTimer()
// Coded by			: Scott Evans
// Created/Modified	: 23/2/98
// Description		: Sets the program timer routine

// Parameters		: None

// Returns			: None

// Notes			: None


void InstallTimer(void)
{
	InstallVsyncCallback(GameTimerCallback);

	#ifdef DEBUG_INFO

	PrintFM("Completed\n");

	#endif
}


// Function			: RemoveTimer()
// Coded by			: Scott Evans
// Created/Modified	: 23/2/98
// Description		: Removes the program timer routine

// Parameters		: None

// Returns			: None

// Notes			: None


void RemoveTimer(void)
{
	RemoveVsyncCallback();

	#ifdef DEBUG_INFO

	PrintFM("Timer function removed\n");

	#endif
}


// Function			: GameTimerCallback()
// Coded by			: Scott Evans
// Created/Modified	: 23/2/98
// Description		: Function to be called each vertical blank

// Parameters		: None

// Returns			: None

// Notes			: None


void GameTimerCallback(void)
{
	timer++;
}


// Function			: GetTimer()
// Coded by			: Scott Evans
// Created/Modified	: 23/2/98
// Description		: Get value of timer

// Parameters		: None 

// Returns			: None

// Notes			: None


u_long GetTimer(void)
{
	return(timer);
}


// Function			: InstallVsyncCallback()
// Coded by			: Scott Evans
// Created/Modified	: 23/2/98
// Description		: Set the vertical blank function

// Parameters		: f - function to call each vertical blank 

// Returns			: None

// Notes			: None


void InstallVsyncCallback(void (*f)(void))
{
	VSyncCallback(f);
}


// Function			: RemoveVsyncCallback()
// Coded by			: Scott Evans
// Created/Modified	: 23/2/98
// Description		: Removes the vertical blank function

// Parameters		: None 

// Returns			: None

// Notes			: None


void RemoveVsyncCallback(void)
{
	VSyncCallback(NULL);
}


// Function			: ResetTimer()
// Coded by			: Scott Evans
// Created/Modified	: 23/2/98
// Description		: Resets the timer variable

// Parameters		: value - new timer value

// Returns			: None

// Notes			: None


void ResetTimer(u_long value)
{
	timer=value;
}