mapnik/plugins/input/topojson/topojson_datasource.cpp

304 lines
9.3 KiB
C++

/*****************************************************************************
*
* This file is part of Mapnik (c++ mapping toolkit)
*
* Copyright (C) 2012 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
*
*****************************************************************************/
#include "topojson_datasource.hpp"
#include "topojson_featureset.hpp"
#include <fstream>
#include <algorithm>
// boost
#include <boost/algorithm/string.hpp>
#include <boost/spirit/include/support_multi_pass.hpp>
#include <boost/geometry/geometries/box.hpp>
#include <boost/geometry/geometries/geometries.hpp>
#include <boost/geometry.hpp>
#include <boost/geometry/extensions/index/rtree/rtree.hpp>
#include <boost/variant.hpp>
// mapnik
#include <mapnik/unicode.hpp>
#include <mapnik/value_types.hpp>
#include <mapnik/box2d.hpp>
#include <mapnik/json/topojson_grammar.hpp>
#include <mapnik/json/topojson_grammar_impl.hpp>
#include <mapnik/json/topojson_utils.hpp>
#include <mapnik/util/variant.hpp>
using mapnik::datasource;
using mapnik::parameters;
DATASOURCE_PLUGIN(topojson_datasource)
struct attr_value_converter : public mapnik::util::static_visitor<mapnik::eAttributeType>
{
mapnik::eAttributeType operator() (mapnik::value_integer /*val*/) const
{
return mapnik::Integer;
}
mapnik::eAttributeType operator() (double /*val*/) const
{
return mapnik::Double;
}
mapnik::eAttributeType operator() (float /*val*/) const
{
return mapnik::Double;
}
mapnik::eAttributeType operator() (bool /*val*/) const
{
return mapnik::Boolean;
}
mapnik::eAttributeType operator() (std::string const& /*val*/) const
{
return mapnik::String;
}
mapnik::eAttributeType operator() (mapnik::value_unicode_string const& /*val*/) const
{
return mapnik::String;
}
mapnik::eAttributeType operator() (mapnik::value_null const& /*val*/) const
{
return mapnik::String;
}
};
struct geometry_type_visitor : public boost::static_visitor<int>
{
int operator() (mapnik::topojson::point const&) const
{
return static_cast<int>(mapnik::datasource::Point);
}
int operator() (mapnik::topojson::multi_point const&) const
{
return static_cast<int>(mapnik::datasource::Point);
}
int operator() (mapnik::topojson::linestring const&) const
{
return static_cast<int>(mapnik::datasource::LineString);
}
int operator() (mapnik::topojson::multi_linestring const&) const
{
return static_cast<int>(mapnik::datasource::LineString);
}
int operator() (mapnik::topojson::polygon const&) const
{
return static_cast<int>(mapnik::datasource::Polygon);
}
int operator() (mapnik::topojson::multi_polygon const&) const
{
return static_cast<int>(mapnik::datasource::Polygon);
}
int operator() (mapnik::topojson::invalid const&) const
{
return -1;
}
};
struct collect_attributes_visitor : public mapnik::util::static_visitor<void>
{
mapnik::layer_descriptor & desc_;
collect_attributes_visitor(mapnik::layer_descriptor & desc):
desc_(desc) {}
void operator() (mapnik::topojson::invalid const& g) {}
template <typename GeomType>
void operator() (GeomType const& g)
{
if (g.props)
{
for (auto const& p : *g.props)
{
desc_.add_descriptor(mapnik::attribute_descriptor(std::get<0>(p),
mapnik::util::apply_visitor(attr_value_converter(),
std::get<1>(p))));
}
}
}
};
topojson_datasource::topojson_datasource(parameters const& params)
: datasource(params),
type_(datasource::Vector),
desc_(topojson_datasource::name(),
*params.get<std::string>("encoding","utf-8")),
filename_(),
inline_string_(),
extent_(),
tr_(new mapnik::transcoder(*params.get<std::string>("encoding","utf-8"))),
tree_(16,1)
{
boost::optional<std::string> inline_string = params.get<std::string>("inline");
if (inline_string)
{
inline_string_ = *inline_string;
}
else
{
boost::optional<std::string> file = params.get<std::string>("file");
if (!file) throw mapnik::datasource_exception("TopoJSON Plugin: missing <file> parameter");
boost::optional<std::string> base = params.get<std::string>("base");
if (base)
filename_ = *base + "/" + *file;
else
filename_ = *file;
}
if (!inline_string_.empty())
{
std::istringstream in(inline_string_);
parse_topojson(in);
}
else
{
#if defined (_WINDOWS)
std::ifstream in(mapnik::utf8_to_utf16(filename_),std::ios_base::in | std::ios_base::binary);
#else
std::ifstream in(filename_.c_str(),std::ios_base::in | std::ios_base::binary);
#endif
if (!in.is_open())
{
throw mapnik::datasource_exception("TopoJSON Plugin: could not open: '" + filename_ + "'");
}
parse_topojson(in);
in.close();
}
}
template <typename T>
void topojson_datasource::parse_topojson(T & stream)
{
using base_iterator_type = std::istreambuf_iterator<char>;
boost::spirit::multi_pass<base_iterator_type> begin =
boost::spirit::make_default_multi_pass(base_iterator_type(stream));
boost::spirit::multi_pass<base_iterator_type> end =
boost::spirit::make_default_multi_pass(base_iterator_type());
static const mapnik::topojson::topojson_grammar<boost::spirit::multi_pass<base_iterator_type> > g;
boost::spirit::standard_wide::space_type space;
bool result = boost::spirit::qi::phrase_parse(begin, end, g, space, topo_);
if (!result)
{
throw mapnik::datasource_exception("topojson_datasource: Failed parse TopoJSON file '" + filename_ + "'");
}
std::size_t count = 0;
for (auto const& geom : topo_.geometries)
{
mapnik::box2d<double> bbox = boost::apply_visitor(mapnik::topojson::bounding_box_visitor(topo_), geom);
if (bbox.valid())
{
if (count == 0)
{
extent_ = bbox;
collect_attributes_visitor assessor(desc_);
boost::apply_visitor(assessor,geom);
}
else
{
extent_.expand_to_include(bbox);
}
tree_.insert(box_type(point_type(bbox.minx(),bbox.miny()),point_type(bbox.maxx(),bbox.maxy())), count);
}
++count;
}
}
topojson_datasource::~topojson_datasource() { }
const char * topojson_datasource::name()
{
return "topojson";
}
boost::optional<mapnik::datasource::geometry_t> topojson_datasource::get_geometry_type() const
{
boost::optional<mapnik::datasource::geometry_t> result;
int multi_type = 0;
std::size_t num_features = topo_.geometries.size();
for (std::size_t i = 0; i < num_features && i < 5; ++i)
{
mapnik::topojson::geometry const& geom = topo_.geometries[i];
int type = boost::apply_visitor(geometry_type_visitor(),geom);
if (type > 0)
{
if (multi_type > 0 && multi_type != type)
{
result.reset(mapnik::datasource::Collection);
return result;
}
else
{
result.reset(static_cast<mapnik::datasource::geometry_t>(type));
}
multi_type = type;
}
}
return result;
}
mapnik::datasource::datasource_t topojson_datasource::type() const
{
return type_;
}
mapnik::box2d<double> topojson_datasource::envelope() const
{
return extent_;
}
mapnik::layer_descriptor topojson_datasource::get_descriptor() const
{
return desc_;
}
mapnik::featureset_ptr topojson_datasource::features(mapnik::query const& q) const
{
// if the query box intersects our world extent then query for features
mapnik::box2d<double> const& b = q.get_bbox();
if (extent_.intersects(b))
{
box_type box(point_type(b.minx(),b.miny()),point_type(b.maxx(),b.maxy()));
return std::make_shared<topojson_featureset>(topo_, *tr_, tree_.find(box));
}
// otherwise return an empty featureset pointer
return mapnik::featureset_ptr();
}
mapnik::featureset_ptr topojson_datasource::features_at_point(mapnik::coord2d const& pt, double tol) const
{
mapnik::box2d<double> query_bbox(pt, pt);
query_bbox.pad(tol);
mapnik::query q(query_bbox);
for (auto const& attr_info : desc_.get_descriptors())
{
q.add_property_name(attr_info.get_name());
}
return features(q);
}