/********************************************************************
**                Image Component Library (ICL)                    **
**                                                                 **
** Copyright (C) 2006-2013 CITEC, University of Bielefeld          **
**                         Neuroinformatics Group                  **
** Website: www.iclcv.org and                                      **
**          http://opensource.cit-ec.de/projects/icl               **
**                                                                 **
** File   : ICLUtils/src/ICLUtils/FPSEstimator.cpp                 **
** Module : ICLUtils                                               **
** Authors: Christof Elbrechter                                    **
**                                                                 **
**                                                                 **
** GNU LESSER GENERAL PUBLIC LICENSE                               **
** This file may be used under the terms of the GNU Lesser General **
** Public License version 3.0 as published by the                  **
**                                                                 **
** Free Software Foundation and appearing in the file LICENSE.LGPL **
** included in the packaging of this file.  Please review the      **
** following information to ensure the license requirements will   **
** be met: http://www.gnu.org/licenses/lgpl-3.0.txt                **
**                                                                 **
** The development of this software was supported by the           **
** Excellence Cluster EXC 277 Cognitive Interaction Technology.    **
** The Excellence Cluster EXC 277 is a grant of the Deutsche       **
** Forschungsgemeinschaft (DFG) in the context of the German       **
** Excellence Initiative.                                          **
**                                                                 **
********************************************************************/

#include <ICLUtils/FPSEstimator.h>
#include <ICLUtils/Macros.h>
#include <cstdio>
namespace icl{
  namespace utils{
    FPSEstimator::FPSEstimator(int n){
      reset(n);
    }
    
    void FPSEstimator::reset(int n){
      if(n<2){
        n = 2;
      }
      m_iN = n;
      m_qTimes.clear();
      for(int i=0;i<n;i++){
        m_qTimes.push_back(Time());
      }
    }
    
    void FPSEstimator::tic() const{
      m_qTimes.push_back(Time::now());
      m_qTimes.pop_front();
    }
      
    float FPSEstimator::getFPSVal() const{
      tic();
      if(m_qTimes.front()==Time::null){
        return -1;
      }else{
        double avgDt = 0;
        
        Time t = m_qTimes.front();
        for(std::deque<Time>::iterator it=++m_qTimes.begin();it!=m_qTimes.end();++it){
          avgDt += ((*it)-t).toMicroSecondsDouble();
          t = *it;
        }
        return 1.0/(avgDt/(1000000.0*(m_iN-1)));
      }
    }
      
    std::string FPSEstimator::getFPSString(const std::string &fmt, int bufferSize) const{
      char *buf = new char[bufferSize];
      sprintf(buf,fmt.c_str(),getFPSVal());
      std::string s(buf);
      delete [] buf;
      return s;
  
    }
      
    void FPSEstimator::showFPS(const std::string &text) const{
      printf("%s:%s\n",text.c_str(),getFPSString().c_str());
    }
    
  } // namespace utils
}