ClippedCast.h

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/********************************************************************
**                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/ClippedCast.h                    **
** 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.GPL  **
** 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.                                          **
**                                                                 **
********************************************************************/

#pragma once

#include <limits>

namespace icl{
  namespace utils{
    template <class T>
    inline T clip(T tX, T tMin, T tMax){ 
      return tX < tMin ? tMin : tX > tMax ? tMax : tX; 
    }
    
    
    template<class T>
    inline bool is_float_type(){
      return false;
    }
    
    template<> inline bool is_float_type<float>() { return true; }  
    template<> inline bool is_float_type<double>() { return true; }  

    template<class S, class D> 
    inline D clipped_cast(S src){
      if(is_float_type<D>()){ //hopefully this is const enough for optimize this expresseion out
        return src < -std::numeric_limits<D>::max() ? -std::numeric_limits<D>::max() : 
        src > std::numeric_limits<D>::max() ? std::numeric_limits<D>::max() : 
        static_cast<D>(src);
      }else{
        return src < std::numeric_limits<D>::min() ? std::numeric_limits<D>::min() : 
        src > std::numeric_limits<D>::max() ? std::numeric_limits<D>::max() : 
        static_cast<D>(src);
      }
    }
    

  #define SPECIALISE_CLIPPED_CAST(T) template<> inline T clipped_cast<T,T>(T t) { return t; }
    SPECIALISE_CLIPPED_CAST(int)
    SPECIALISE_CLIPPED_CAST(unsigned int)
    SPECIALISE_CLIPPED_CAST(char)
    SPECIALISE_CLIPPED_CAST(unsigned char)
    SPECIALISE_CLIPPED_CAST(short)
    SPECIALISE_CLIPPED_CAST(unsigned short)
    SPECIALISE_CLIPPED_CAST(long)
    SPECIALISE_CLIPPED_CAST(unsigned long)
    SPECIALISE_CLIPPED_CAST(bool)
    SPECIALISE_CLIPPED_CAST(float)
    SPECIALISE_CLIPPED_CAST(double)
  #undef SPECIALISE_CLIPPED_CAST

  } // namespace utils
}