sources/android/ndk_helper/perfMonitor.cpp

/*
 * Copyright 2013 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "perfMonitor.h"

namespace ndk_helper
{

PerfMonitor::PerfMonitor() :
                last_tick_( 0.f ),
                tv_last_sec_( 0 ),
                tickindex_( 0 ),
                ticksum_( 0 )
{
    for( int32_t i = 0; i < NUM_SAMPLES; ++i )
        ticklist_[i] = 0;
}

PerfMonitor::~PerfMonitor()
{
}

double PerfMonitor::UpdateTick( double currentTick )
{
    ticksum_ -= ticklist_[tickindex_];
    ticksum_ += currentTick;
    ticklist_[tickindex_] = currentTick;
    tickindex_ = (tickindex_ + 1) % NUM_SAMPLES;

    return ((double) ticksum_ / NUM_SAMPLES);
}

bool PerfMonitor::Update( float &fFPS )
{
    struct timeval Time;
    gettimeofday( &Time, NULL );

    double time = Time.tv_sec + Time.tv_usec * 1.0 / 1000000.0;
    double tick = time - last_tick_;
    double d = UpdateTick( tick );
    last_tick_ = time;

    if( Time.tv_sec - tv_last_sec_ >= 1 )
    {
        double time = Time.tv_sec + Time.tv_usec * 1.0 / 1000000.0;
        current_FPS_ = 1.f / d;
        tv_last_sec_ = Time.tv_sec;
        fFPS = current_FPS_;
        return true;
    }
    else
    {
        fFPS = current_FPS_;
        return false;
    }
}

}   //namespace ndkHelper