mapnik/plugins/input/topojson/topojson_featureset.cpp
2015-01-27 22:20:03 -08:00

388 lines
13 KiB
C++

/*****************************************************************************
*
* This file is part of Mapnik (c++ mapping toolkit)
*
* Copyright (C) 2014 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/feature.hpp>
#include <mapnik/feature_factory.hpp>
#include <mapnik/json/topology.hpp>
#include <mapnik/util/variant.hpp>
// stl
#include <string>
#include <vector>
#include <fstream>
// boost
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wunused-parameter"
#pragma GCC diagnostic ignored "-Wunused-variable"
#pragma GCC diagnostic ignored "-Wunused-local-typedef"
#include <boost/range/adaptor/reversed.hpp>
#include <boost/range/adaptor/sliced.hpp>
#include <boost/geometry.hpp>
#include <boost/geometry/algorithms/simplify.hpp>
#include <boost/geometry/geometries/register/point.hpp>
#include <boost/geometry/geometries/register/linestring.hpp>
#pragma GCC diagnostic pop
#include "topojson_featureset.hpp"
BOOST_GEOMETRY_REGISTER_POINT_2D(mapnik::topojson::coordinate, double, boost::geometry::cs::cartesian, x, y)
BOOST_GEOMETRY_REGISTER_LINESTRING(std::vector<mapnik::topojson::coordinate>)
namespace mapnik { namespace topojson {
struct attribute_value_visitor
{
public:
attribute_value_visitor(mapnik::transcoder const& tr)
: tr_(tr) {}
mapnik::value operator()(std::string const& val) const
{
return mapnik::value(tr_.transcode(val.c_str()));
}
template <typename T>
mapnik::value operator()(T const& val) const
{
return mapnik::value(val);
}
mapnik::transcoder const& tr_;
};
template <typename T>
void assign_properties(mapnik::feature_impl & feature, T const& geom, mapnik::transcoder const& tr)
{
if ( geom.props)
{
for (auto const& p : *geom.props)
{
feature.put_new(std::get<0>(p), mapnik::util::apply_visitor(attribute_value_visitor(tr),std::get<1>(p)));
}
}
}
template <typename Context>
struct feature_generator
{
feature_generator(Context & ctx, mapnik::transcoder const& tr, topology const& topo, std::size_t feature_id)
: ctx_(ctx),
tr_(tr),
topo_(topo),
feature_id_(feature_id) {}
feature_ptr operator() (point const& pt) const
{
mapnik::feature_ptr feature(mapnik::feature_factory::create(ctx_,feature_id_));
std::unique_ptr<geometry_type> point_ptr(new geometry_type(geometry_type::types::Point));
double x = pt.coord.x;
double y = pt.coord.y;
if (topo_.tr)
{
x = x * (*topo_.tr).scale_x + (*topo_.tr).translate_x;
y = y * (*topo_.tr).scale_y + (*topo_.tr).translate_y;
}
point_ptr->move_to(x,y);
feature->paths().push_back(point_ptr.release());
assign_properties(*feature, pt, tr_);
return feature;
}
feature_ptr operator() (multi_point const& multi_pt) const
{
mapnik::feature_ptr feature(mapnik::feature_factory::create(ctx_,feature_id_));
for (auto const& pt : multi_pt.points)
{
std::unique_ptr<geometry_type> point_ptr(new geometry_type(geometry_type::types::Point));
double x = pt.x;
double y = pt.y;
if (topo_.tr)
{
x = x * (*topo_.tr).scale_x + (*topo_.tr).translate_x;
y = y * (*topo_.tr).scale_y + (*topo_.tr).translate_y;
}
point_ptr->move_to(x,y);
feature->paths().push_back(point_ptr.release());
}
assign_properties(*feature, multi_pt, tr_);
return feature;
}
feature_ptr operator() (linestring const& line) const
{
mapnik::feature_ptr feature(mapnik::feature_factory::create(ctx_,feature_id_));
std::unique_ptr<geometry_type> line_ptr(new geometry_type(geometry_type::types::LineString));
double px = 0, py = 0;
index_type arc_index = line.ring;
bool first = true;
for (auto pt : topo_.arcs[arc_index].coordinates)
{
double x = pt.x;
double y = pt.y;
if (topo_.tr)
{
x = (px += x) * (*topo_.tr).scale_x + (*topo_.tr).translate_x;
y = (py += y) * (*topo_.tr).scale_y + (*topo_.tr).translate_y;
}
if (first)
{
first = false;
line_ptr->move_to(x,y);
}
else
{
line_ptr->line_to(x,y);
}
}
feature->paths().push_back(line_ptr.release());
assign_properties(*feature, line, tr_);
return feature;
}
feature_ptr operator() (multi_linestring const& multi_line) const
{
mapnik::feature_ptr feature(mapnik::feature_factory::create(ctx_,feature_id_));
for (auto const& index : multi_line.rings)
{
std::unique_ptr<geometry_type> line_ptr(new geometry_type(geometry_type::types::LineString));
double px = 0, py = 0;
bool first = true;
bool reverse = index < 0;
index_type arc_index = reverse ? std::abs(index) - 1 : index;
for (auto pt : topo_.arcs[arc_index].coordinates)
{
double x = pt.x;
double y = pt.y;
if (topo_.tr)
{
x = (px += x) * (*topo_.tr).scale_x + (*topo_.tr).translate_x;
y = (py += y) * (*topo_.tr).scale_y + (*topo_.tr).translate_y;
}
if (first)
{
first = false;
line_ptr->move_to(x,y);
}
else
{
line_ptr->line_to(x,y);
}
}
feature->paths().push_back(line_ptr.release());
}
assign_properties(*feature, multi_line, tr_);
return feature;
}
feature_ptr operator() (polygon const& poly) const
{
mapnik::feature_ptr feature(mapnik::feature_factory::create(ctx_,feature_id_));
std::unique_ptr<geometry_type> poly_ptr(new geometry_type(geometry_type::types::Polygon));
std::vector<mapnik::topojson::coordinate> processed_coords;
for (auto const& ring : poly.rings)
{
bool first = true;
for (auto const& index : ring)
{
double px = 0, py = 0;
bool reverse = index < 0;
index_type arc_index = reverse ? std::abs(index) - 1 : index;
auto const& coords = topo_.arcs[arc_index].coordinates;
processed_coords.clear();
processed_coords.reserve(coords.size());
for (auto const& pt : coords )
{
double x = pt.x;
double y = pt.y;
if (topo_.tr)
{
transform const& tr = *topo_.tr;
x = (px += x) * tr.scale_x + tr.translate_x;
y = (py += y) * tr.scale_y + tr.translate_y;
}
processed_coords.emplace_back(coordinate{x,y});
}
// simplify
std::vector<mapnik::topojson::coordinate> simplified(processed_coords.size());
boost::geometry::simplify(processed_coords, simplified, 2);
using namespace boost::adaptors;
if (reverse)
{
for (auto const& c : simplified | reversed | sliced(0, simplified.size()-1))
{
if (first)
{
first = false;
poly_ptr->move_to(c.x,c.y);
}
else poly_ptr->line_to(c.x,c.y);
}
}
else
{
for (auto const& c : simplified | sliced(0, simplified.size()-1))
{
if (first)
{
first = false;
poly_ptr->move_to(c.x,c.y);
}
else poly_ptr->line_to(c.x,c.y);
}
}
}
poly_ptr->close_path();
}
feature->paths().push_back(poly_ptr.release());
assign_properties(*feature, poly, tr_);
return feature;
}
feature_ptr operator() (multi_polygon const& multi_poly) const
{
mapnik::feature_ptr feature(mapnik::feature_factory::create(ctx_,feature_id_));
std::vector<mapnik::topojson::coordinate> processed_coords;
for (auto const& poly : multi_poly.polygons)
{
std::unique_ptr<geometry_type> poly_ptr(new geometry_type(geometry_type::types::Polygon));
for (auto const& ring : poly)
{
bool first = true;
for (auto const& index : ring)
{
double px = 0, py = 0;
bool reverse = index < 0;
index_type arc_index = reverse ? std::abs(index) - 1 : index;
auto const& coords = topo_.arcs[arc_index].coordinates;
processed_coords.clear();
processed_coords.reserve(coords.size());
for (auto const& pt : coords )
{
double x = pt.x;
double y = pt.y;
if (topo_.tr)
{
x = (px += x) * (*topo_.tr).scale_x + (*topo_.tr).translate_x;
y = (py += y) * (*topo_.tr).scale_y + (*topo_.tr).translate_y;
}
processed_coords.emplace_back(coordinate{x,y});
}
using namespace boost::adaptors;
if (reverse)
{
for (auto const& c : (processed_coords | reversed | sliced(0,processed_coords.size() - 1)))
{
if (first)
{
first = false;
poly_ptr->move_to(c.x,c.y);
}
else poly_ptr->line_to(c.x,c.y);
}
}
else
{
for (auto const& c : processed_coords | sliced(0,processed_coords.size() - 1))
{
if (first)
{
first = false;
poly_ptr->move_to(c.x,c.y);
}
else poly_ptr->line_to(c.x,c.y);
}
}
}
poly_ptr->close_path();
}
feature->paths().push_back(poly_ptr.release());
}
assign_properties(*feature, multi_poly, tr_);
return feature;
}
template<typename T>
feature_ptr operator() (T const& ) const
{
return feature_ptr();
}
Context & ctx_;
mapnik::transcoder const& tr_;
topology const& topo_;
std::size_t feature_id_;
};
}}
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_ (0) {}
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();
}