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glt/frame.cpp

Go to the documentation of this file.

#include "frame.h"

#include <cstdio>
using namespace std;

GltFrameRate::GltFrameRate(const int sampleSize)
: _frames(0), 
  _step(0.200),
  _lastFrameRate(0.0), 
  _lastFrameTime(0.0),
  _buffer(sampleSize)
{
    _lastCalc = _timer.elapsed();
}

GltFrameRate::~GltFrameRate()
{
}

GltFrameRate &
GltFrameRate::operator++()
{
    _frames++;
    _buffer.push_back(_timer.elapsed());
    
    // Recalculate frame rate and frame time
    // if we have sufficient samples and
    // enough time has elapsed.
    
    if (_buffer.size()>=2)
    {
        if ((_buffer.back()-_lastCalc)>=_step)
        {
            _lastCalc      = _buffer.back();
            _lastFrameTime = double(_buffer.back()-_buffer.front())/double(_buffer.size()-1);
            _lastFrameRate = 1.0/_lastFrameTime;
        }
    }
    
    return *this;
}

double GltFrameRate::elapsedTime() const { return _timer.elapsed(); }
int    GltFrameRate::totalFrames() const { return _frames;          }

double GltFrameRate::frameRate()   const { return _lastFrameRate; }
double GltFrameRate::frameTime()   const { return _lastFrameTime; }

std::string 
GltFrameRate::summary() const
{
    char buffer[1024];
    sprintf
    (
        buffer,
        "%3.0lf fps",
        frameRate()
    );
    return buffer;
}

std::string 
GltFrameRate::detailed() const
{
    char buffer[1024];
    sprintf
    (
        buffer,
        "%5.3lf sec %3.0lf fps",
        frameTime(),
        frameRate()
    );
    return buffer;
}

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