cfpscounter.cpp

一个基于symbian s60 3rd 的3D汽车游戏演示程序,模拟器上编译通过。

   /*
============================================================================
    * 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();
        }
    }