mapnik/include/vertex_transform.hh

/* This file is part of Mapnik (c++ mapping toolkit)
 * Copyright (C) 2005 Artem Pavlenko
 *
 * Mapnik is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */

//$Id$

#ifndef VERTEX_TRANSFORM_HH
#define VERTEX_TRANSFORM_HH

#include "vertex.hh"
#include "envelope.hh"

namespace mapnik
{
    template <typename T0 ,typename T1,int shift=8>
    struct Shift
    {
	typedef T0 value_type;
	typedef T1 return_type;
	static return_type apply(value_type val)
	{
	    return static_cast<return_type>(val*(1<<shift));
	}
    };

    template <typename T0,typename T1>
    struct Shift<T0,T1,0> 
    {
	typedef T0 value_type;
	typedef T1 return_type;
	static return_type apply(value_type val)
	{
	    return static_cast<return_type>(val);
	}
    };

    template <typename T>
    struct Shift<T,T,0>
    {
	typedef T value_type;
	typedef T return_type;
	static T& apply(T& val)
	{
	    return val;
	}
    };

    typedef Shift<double,double,0> NO_SHIFT;
    typedef Shift<double,int,0> SHIFT0;
    typedef Shift<double,int,8> SHIFT8;
    
    
    template <typename T0,typename T1,typename Trans>
    struct view_transform;
    
    template <typename Trans>
    struct view_transform <vertex2d,vertex2d,Trans>   
    {
	
    };
    
    template <typename Trans>
    struct view_transform <vertex2d,vertex2i,Trans>   
    {
	
    };

    template <typename Trans>
    struct view_transform<Envelope<double>,Envelope<double>,Trans>
    {
	
    };
}

#endif //VERTEX_TRANSFORM_HH