www.pudn.com > RCApp-src.zip > FPSCounter.cpp

/* 
	RedEye Project (http://members.ozemail.com.au/~ndmcevoy/) 
	Copyright (C) 2003  Nick McEvoy 
 
	This library is free software; you can redistribute it and/or 
	modify it under the terms of the GNU Library General Public 
	License as published by the Free Software Foundation; either 
	version 2 of the License, or (at your option) any later version. 
 
	This library is distributed in the hope that it will be useful, 
	but WITHOUT ANY WARRANTY; without even the implied warranty of 
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU 
	Library General Public License for more details. 
 
	You should have received a copy of the GNU Library General Public 
	License along with this library; if not, write to the Free 
	Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 
 
	----------------------------------------------------------------- 
 
		Commented for use with Doxygen (http://www.doxygen.org) 
 
	----------------------------------------------------------------- 
*/ 
 
/*! \file FPSCounter.cpp 
 *	\brief Frames per second counter. 
 * 
 *		This file contains the game frames per second counter. 
 */ 
 
// GLUT includes 
#include  
 
// RedEye includes 
#include "FPSCounter.h" 
 
//! The one and only instance 
reFPSCounter* reFPSCounter::mpInstance = 0; 
 
 
 
 
reFPSCounter::reFPSCounter() 
{ 
	mfFPS = 0; 
	miFrameNo = 0; 
	miLastFrameNo = 0; 
	miLastTimeMs = 0; 
} 
 
 
 
 
reFPSCounter::~reFPSCounter() 
{ 
	mpInstance = 0; 
} 
 
 
 
 
reFPSCounter* 
reFPSCounter::GetInstance() 
{ 
	if (mpInstance == 0) 
	{ 
		mpInstance = new reFPSCounter; 
	} 
	return mpInstance; 
} 
 
 
 
 
void 
reFPSCounter::Display() 
{ 
	miFrameNo++; 
 
	int iCurrentTimeMs = glutGet(GLUT_ELAPSED_TIME); 
	int iFrameNoDiff = miFrameNo - miLastFrameNo; 
 
	// Only recalculate every so often 
	if (iFrameNoDiff > 25) 
	{ 
		int iTimeDiffFPS = iCurrentTimeMs - miLastTimeMs; 
		mfFPS = (iFrameNoDiff / (float)iTimeDiffFPS) * 1000.0f; 
		miLastTimeMs = iCurrentTimeMs; 
		miLastFrameNo = miFrameNo; 
	} 
}