mapnik/include/mapnik/vertex_transform.hpp
2010-06-02 11:03:30 +00:00

93 lines
2.3 KiB
C++

/*****************************************************************************
*
* This file is part of Mapnik (c++ mapping toolkit)
*
* Copyright (C) 2006 Artem Pavlenko
*
* 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 St, Fifth Floor, Boston, MA 02110-1301 USA
*
*****************************************************************************/
//$Id: vertex_transform.hpp 39 2005-04-10 20:39:53Z pavlenko $
#ifndef VERTEX_TRANSFORM_HPP
#define VERTEX_TRANSFORM_HPP
// mapnik
#include <mapnik/box2d.hpp>
#include <mapnik/vertex.hpp>
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<box2d<double>,box2d<double>,Trans>
{
};
}
#endif //VERTEX_TRANSFORM_HPP