cfpscounter.cpp

S60 3D游戏引擎开发案例 S60 3D游戏引擎开发案例

   /*
============================================================================
    * Name : CFpsCounter.cpp
    * Part of : Example3D
    * Description : Definition of CFpsCounter
    * Copyright (c) 2007 Nokia Corporation
============================================================================
    */

// INCLUDES
#include "CFpsCounter.h"
#include <hal.h>

// MEMBER FUNCTIONS
CFpsCounter* CFpsCounter::NewL( TInt aInterval )
	{
	CFpsCounter* self = new( ELeave )CFpsCounter( aInterval );
	return self;
	}

CFpsCounter::CFpsCounter( TInt aInterval )
	{
	HAL::Get( HALData::ESystemTickPeriod, iTicksPerSecond );
	iTicksPerSecond = 1000000 / iTicksPerSecond;
	SetInterval( aInterval );
	iFrames = 0;
	iSeconds=0;
	iStartTicks = User::TickCount();
	}
	
CFpsCounter::~CFpsCounter()
	{
	}
	
int CFpsCounter::Fps()
	{
	return iFps;
	}

void CFpsCounter::SetInterval( TInt aInterval )
	{
	iSecs = aInterval;
	iInterval = ( iTicksPerSecond * aInterval );
	}

void CFpsCounter::Update()
	{
	TInt cticks = User::TickCount();
	iFrames++;
	
	if ( ( cticks - iStartTicks ) > iInterval )
		{
		TInt dif = cticks - iStartTicks;
		iFps = ( ( iFrames * ( iTicksPerSecond ) ) / dif );
		iFrames = 0;
		iSeconds += iSecs;
		iStartTicks = User::TickCount();
		}
	}