mapnik/include/mapnik/view_strategy.hpp
2021-01-05 14:39:07 +00:00

95 lines
2.8 KiB
C++

/*****************************************************************************
*
* This file is part of Mapnik (c++ mapping toolkit)
*
* Copyright (C) 2021 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
*
*****************************************************************************/
#ifndef MAPNIK_VIEW_STRATEGY_HPP
#define MAPNIK_VIEW_STRATEGY_HPP
// mapnik
#include <mapnik/view_transform.hpp>
#include <mapnik/safe_cast.hpp>
// boost
#include <boost/geometry/core/coordinate_type.hpp>
#include <boost/geometry/core/access.hpp>
namespace mapnik
{
struct view_strategy
{
view_strategy(view_transform const& tr)
: tr_(tr) {}
template <typename P1, typename P2>
inline bool apply(P1 const& p1, P2 & p2) const
{
using coordinate_type = typename boost::geometry::coordinate_type<P2>::type;
double x = boost::geometry::get<0>(p1);
double y = boost::geometry::get<1>(p1);
tr_.forward(&x,&y);
boost::geometry::set<0>(p2, safe_cast<coordinate_type>(x));
boost::geometry::set<1>(p2, safe_cast<coordinate_type>(y));
return true;
}
template <typename P1, typename P2>
inline P2 execute(P1 const& p1, bool & status) const
{
P2 p2;
status = apply(p1, p2);
return p2;
}
view_transform const& tr_;
};
struct unview_strategy
{
unview_strategy(view_transform const& tr)
: tr_(tr) {}
template <typename P1, typename P2>
inline bool apply(P1 const& p1, P2 & p2) const
{
using coordinate_type = typename boost::geometry::coordinate_type<P2>::type;
double x = boost::geometry::get<0>(p1);
double y = boost::geometry::get<1>(p1);
tr_.backward(&x,&y);
boost::geometry::set<0>(p2, static_cast<coordinate_type>(x));
boost::geometry::set<1>(p2, static_cast<coordinate_type>(y));
return true;
}
template <typename P1, typename P2>
inline P2 execute(P1 const& p1, bool & status) const
{
P2 p2;
status = apply(p1, p2);
return p2;
}
view_transform const& tr_;
};
}
#endif // MAPNIK_VIEW_STRATEGY_HPP