mapnik/plugins/input/topojson/topojson_featureset.cpp

68 lines
2.4 KiB
C++

/*****************************************************************************
*
* This file is part of Mapnik (c++ mapping toolkit)
*
* Copyright (C) 2015 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
*
*****************************************************************************/
// mapnik
#include <mapnik/json/topology.hpp>
#include <mapnik/json/topojson_utils.hpp>
// stl
#include <string>
#include <vector>
#include <fstream>
#pragma GCC diagnostic push
#include <mapnik/warning_ignore.hpp>
#include <boost/range/adaptor/reversed.hpp>
#pragma GCC diagnostic pop
#include "topojson_featureset.hpp"
topojson_featureset::topojson_featureset(mapnik::topojson::topology const& topo,
mapnik::transcoder const& tr,
array_type && index_array)
: ctx_(std::make_shared<mapnik::context_type>()),
topo_(topo),
tr_(tr),
index_array_(std::move(index_array)),
index_itr_(index_array_.begin()),
index_end_(index_array_.end()),
feature_id_(1) {}
topojson_featureset::~topojson_featureset() {}
mapnik::feature_ptr topojson_featureset::next()
{
if (index_itr_ != index_end_)
{
topojson_datasource::item_type const& item = *index_itr_++;
std::size_t index = item.second;
if ( index < topo_.geometries.size())
{
mapnik::topojson::geometry const& geom = topo_.geometries[index];
mapnik::feature_ptr feature = mapnik::util::apply_visitor(
mapnik::topojson::feature_generator<mapnik::context_ptr>(ctx_, tr_, topo_, feature_id_++),
geom);
return feature;
}
}
return mapnik::feature_ptr();
}