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Problem with FPS in fullscreen...

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I am having some trouble with my FPS counter in fullscreen mode... In Windowed, it works. Here is my code:
void Timer::Update () 
{
	if (m_blnPerf_flag) 
		QueryPerformanceCounter ((LARGE_INTEGER *) &m_nCur_time); 
	else 
		m_nCur_time = timeGetTime (); 
   
	m_fTime_elapsed = (m_nCur_time - m_nLast_time) * m_fTime_scale;
	m_nLast_time = m_nCur_time;
	
	m_fClock += (m_fTime_elapsed * m_fFactor);
	if (m_fClock >= 1.0f) 
	{
		m_nSeconds++;
		m_fClock = 0.0f;
	}
	if (m_nSeconds >= 60) 
	{
		m_nMinutes++;
		m_nSeconds = 0;
	}
	if (m_nMinutes >= 60) 
	{
		m_nHours++;
		m_nMinutes = 0;
	}
	if (m_nHours >= 24)
		m_nHours = 0;

	m_fStamp = 0.0f;
	m_fStamp += m_fClock;
	m_fStamp += m_nSeconds;
	m_fStamp += m_nMinutes * 100; 
	m_fStamp += m_nHours * 10000;
}

Thanks in advance!

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What is m_nCur_time declared as? If it's less than 8 bytes, you're getting undefined behaviour by casting it to a LARGE_INTEGER

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LONGLONG m_nCur_time;

It doesn't work because it always returns 1 when I do 1/m_fTime_elapsed.

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Anyone know why the code would work in windowed mode and not in fullscreen?

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Quote:
Original post by cppcdr
Anyone know why the code would work in windowed mode and not in fullscreen?
All I can guess is your FPS is higher, and you're having precision issues. Are you using timeGetTime() or QueryPerformanceCounter()? If you get too high a FPS, timeGetTime() will say that 0ms have elapsed since the last frame, which will probably cause problems.

Quote:
Original post by cppcdr
LONGLONG m_nCur_time;

It doesn't work because it always returns 1 when I do 1/m_fTime_elapsed.
Then what is the value of m_fTime_elapsed? 1.0f? And what is m_fTime_scale set to?

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I have checked my FPS with an external FPS counter and it gives me the same value when I am in windowed mode as my FPS counter (~250). When I go to windowed mode, my FPS counter marks 1, and the other counter (the one that I didn't make) says 300.

m_fTime_scale is a variable that I use to slow down time or speed it up. I find it is an easy way to modify the speed of my game. If I set it lower than 1.0f, it slows down, and if I set it higher, it speeds-up.

As for the m_fTime_elapsed, I don't know. I try to run the debugging in fullscreen but my computer refuses to do it...
When I do my debugging, it is in windowed mode...

How do I debug in fullscreen?

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You're not using m_fFactor (which I presume is your clock frequency) in your calculation of m_fTime_elapsed...

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OOPS! I made a mistake!

m_fTime_scale is the clock frequency.
m_fFactor is the time scale factor.

Humm...mayby I should rename the variables...

Anyway, is there any reason that it should be diffrent in fullscreen or in windowed?

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There's no reason the code would work differently in fullscreen. All I can suggest is that you're initializing your variables differently in fullscreen, giving different results.

Try logging the value of the variables every second or so (Not every frame) and see if that helps you.

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Quote:
Original post by cppcdr
How would you suggest logging the variables?
printf(), OutputDebugString(), write them to a file, send them over a socket, render them in-game, anything.

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