mapnik/include/mapnik/symbolizer_hash.hpp

65 lines
2.2 KiB
C++

/*****************************************************************************
*
* This file is part of Mapnik (c++ mapping toolkit)
*
* Copyright (C) 2013 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_SYMBOLIZER_HASH_HPP
#define MAPNIK_SYMBOLIZER_HASH_HPP
#include <mapnik/map.hpp>
#include <mapnik/feature_type_style.hpp>
#include <boost/functional/hash.hpp>
#include <boost/variant/static_visitor.hpp>
namespace mapnik {
struct symbolizer_hash
{
template <typename T>
static std::size_t value(T const& /*sym*/)
{
return 0;
}
// specialisation for polygon_symbolizer
static std::size_t value(polygon_symbolizer const& sym)
{
std::size_t seed = Polygon;
boost::hash_combine(seed, sym.get_fill().rgba());
boost::hash_combine(seed, sym.get_opacity());
return seed;
}
// specialisation for line_symbolizer
static std::size_t value(line_symbolizer const& sym)
{
std::size_t seed = LineString;
boost::hash_combine(seed, sym.get_stroke().get_color().rgba());
boost::hash_combine(seed, sym.get_stroke().get_width());
boost::hash_combine(seed, sym.get_stroke().get_opacity());
boost::hash_combine(seed, static_cast<int>(sym.get_stroke().get_line_cap()));
boost::hash_combine(seed, static_cast<int>(sym.get_stroke().get_line_join()));
return seed;
}
};
}
#endif // MAPNIK_SYMBOLIZER_HASH_HPP