cvd/la.h

/*                       
    This file is part of the CVD Library.

    Copyright (C) 2005 The Authors

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 
    51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
*/
#ifndef CVD_LA_H
#define CVD_LA_H

#include <iostream>
#include <cvd/internal/is_pod.h>

namespace CVD {


  // CVD::La
  // Template class to represent luminance and alpha components
  //
  template <typename T>
    class La
    {
    public:
      La() {}
    La(T l, T a) : luminance(l), alpha(a) {}

      T luminance; 
      T alpha; 

      La<T>& operator=(const La<T>& c)
    {luminance = c.luminance; alpha = c.alpha; return *this;}

      template <typename T2>
    La<T>& operator=(const La<T2>& c){
    luminance = static_cast<T>(c.luminance);
    alpha = static_cast<T>(c.alpha); 
    return *this;
      }
   
      bool operator==(const La<T>& c) const
      {return luminance == c.luminance && alpha == c.alpha;}
      
      bool operator!=(const La<T>& c) const
      {return luminance != c.luminance || alpha != c.alpha;}
      
    };
  
  template <typename T>
    std::ostream& operator <<(std::ostream& os, const La<T>& x)
    {
      return os << "(" << x.luminance << "," << x.alpha << ")";
    }
  
  inline std::ostream& operator <<(std::ostream& os, const La<unsigned char>& x)
  {
    return os << "(" << static_cast<unsigned int>(x.luminance) << ","
          << static_cast<unsigned int>(x.alpha) << ")";
  }
  
#ifndef DOXYGEN_IGNORE_INTERNAL
  namespace Internal
  {
    template<class C> struct is_POD<La<C> >
      {
    enum { is_pod = is_POD<C>::is_pod };
      };
  }
#endif
  
  
  
} // end namespace 
#endif