C++ - Win32 FPS Counter

[Spikey]

I found this timer class I was using a long time ago, it's only for win32, but oh well. You can use it to find out what the refresh rate of your window is, aka FPS (Frames per second). This example outputs the frames per second onto the windows title bar. Enjoy

PerfTimer.h

Code: Select all

#ifndef _PERFTIMER_H
#define _PERFTIMER_H

#include <windows.h>
#include <string>
#include <mmsystem.h> 
#include <ctime>
using namespace std;

#define STRING_SIZE    255

class PerfTimer
{
protected:
	double m_TimeScale;
	double m_Time;
	double m_DeltaTime;

	unsigned int m_FrameCount;
	double m_ElapsedTime ;
	TCHAR *m_Buffer; 
	wstring m_Output;

public:
	PerfTimer();
        ~PerfTimer();
	double GetTime();
	void SetTime();
	double DeltaTime(PerfTimer & P1);
	void OutputFrameRate(HWND & windowHandle);
};

PerfTimer.cpp

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#include "PerfTimer.h"

PerfTimer::PerfTimer()
{
	__int64 countsPerSecond = 0;
	if(QueryPerformanceFrequency((LARGE_INTEGER*)&countsPerSecond) != 0)
	{
		m_TimeScale = 1.0 / (double)countsPerSecond;
	}
	else
	{
		m_TimeScale = 0.0;
		m_Time = 0.0;	// set to zero if no performance timer available
	}
	m_FrameCount = 0;
	m_ElapsedTime = 0.0;
        m_Buffer = new TCHAR[STRING_SIZE];
}

PerfTimer::~PerfTimer() {
       delete[] m_Buffer;
}

double PerfTimer::GetTime()
{
	return m_Time;
}

void PerfTimer::SetTime()
{
	__int64 currentTime = 0;
	QueryPerformanceCounter((LARGE_INTEGER*)&currentTime);
	m_Time = currentTime * m_TimeScale;
}

double PerfTimer::DeltaTime(PerfTimer & P1)
{
	m_DeltaTime = GetTime() - P1.GetTime();
	return m_DeltaTime;
}

void PerfTimer::OutputFrameRate(HWND & windowHandle)
{
	// increment the frame count
	m_FrameCount++;

	// calculate how much time has passed since the last frame
	m_ElapsedTime += m_DeltaTime;
	// if 1 second has passed
	if( m_ElapsedTime >= 1.0 )
	{
		// calculate frames per second.
		// FPS = frameCnt / timeElapsed however only computed when elapsedTime = 1.0 
		// Therefore FPS = frameCnt / 1.0 = frameCnt.

		m_Output = L"Frames Per Second = ";
		_itow_s(m_FrameCount,m_Buffer,20,10);
		m_Output += m_Buffer;

		// set the window caption 
		SetWindowText(windowHandle, m_Output.c_str());

		// Reset
		m_FrameCount = 0;
		m_ElapsedTime = 0.0f;
	}
}

Main.cpp, in your main winmain loop:

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        ...

	PerfTimer P1;
	PerfTimer P2;
	P1.SetTime();
	double sleepElapsedTime = 0.0;

	// Game loop!
	while (1)
	{
		
		P2.SetTime();	// Get current time
		sleepElapsedTime += P2.DeltaTime ( P1 );     // Get Delta time
		P2.OutputFrameRate( hwnd );		          // Output FPS to caption (Pass the window handle)		
			
		SwapBuffers(hDC);

		while (PeekMessage (&msg, NULL, 0, 0, PM_NOREMOVE))		
		{
			if (!GetMessage (&msg, NULL, 0, 0))			
			{
				PostQuitMessage(0);
				break;
			}

			TranslateMessage (&msg);
			DispatchMessage (&msg);
		}

		P1 = P2;		
	}

[eatcomics]

You know you've got a lot of cool code... Why don't you post here more often??? Just kidding, I might use that sometime thanks.... And thanks for all the other code snippets y'all... I was too lazy to post thanks on all of them so I just posted on the last one I read :P but anyways thanks for the contributions!