mapnik/plugins/input/shape/shape_io.cpp
2017-05-05 13:02:01 +02:00

288 lines
8.3 KiB
C++

/*****************************************************************************
*
* This file is part of Mapnik (c++ mapping toolkit)
*
* Copyright (C) 2017 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 "shape_io.hpp"
// mapnik
#include <mapnik/debug.hpp>
#include <mapnik/make_unique.hpp>
#include <mapnik/datasource.hpp>
#include <mapnik/util/is_clockwise.hpp>
#include <mapnik/geometry/correct.hpp>
using mapnik::datasource_exception;
const std::string shape_io::SHP = ".shp";
const std::string shape_io::SHX = ".shx";
const std::string shape_io::DBF = ".dbf";
const std::string shape_io::INDEX = ".index";
shape_io::shape_io(std::string const& shape_name, bool open_index)
: type_(shape_null),
shp_(shape_name + SHP),
shx_(shape_name + SHX),
dbf_(shape_name + DBF),
reclength_(0),
id_(0)
{
bool ok = (shp_.is_open() && dbf_.is_open());
if (!ok)
{
throw datasource_exception("Shape Plugin: cannot read shape file '" + shape_name + "'");
}
if (open_index)
{
try
{
index_ = std::make_unique<shape_file>(shape_name + INDEX);
}
catch (...)
{
MAPNIK_LOG_WARN(shape) << "shape_io: Could not open index=" << shape_name << INDEX;
}
}
if (!index_ && !shx_.is_open())
{
throw datasource_exception("Shape Plugin: cannot read shape index file '" + shape_name + ".shx'");
}
}
shape_io::~shape_io() {}
void shape_io::move_to(std::streampos pos)
{
shp_.seek(pos);
id_ = shp_.read_xdr_integer();
reclength_ = shp_.read_xdr_integer();
}
shape_file& shape_io::shp()
{
return shp_;
}
shape_file& shape_io::shx()
{
return shx_;
}
dbf_file& shape_io::dbf()
{
return dbf_;
}
void shape_io::read_bbox(shape_file::record_type & record, mapnik::box2d<double> & bbox)
{
double lox = record.read_double();
double loy = record.read_double();
double hix = record.read_double();
double hiy = record.read_double();
bbox.init(lox, loy, hix, hiy);
}
mapnik::geometry::geometry<double> shape_io::read_polyline(shape_file::record_type & record)
{
mapnik::geometry::geometry<double> geom; // default empty
int num_parts = record.read_ndr_integer();
int num_points = record.read_ndr_integer();
if (num_parts == 1)
{
mapnik::geometry::line_string<double> line;
line.reserve(num_points);
record.skip(4);
for (int i = 0; i < num_points; ++i)
{
double x = record.read_double();
double y = record.read_double();
line.emplace_back(x, y);
}
geom = std::move(line);
}
else
{
std::vector<int> parts;
parts.resize(num_parts);
std::for_each(parts.begin(), parts.end(), [&](int & part) { part = record.read_ndr_integer();});
int start, end;
mapnik::geometry::multi_line_string<double> multi_line;
multi_line.reserve(num_parts);
for (int k = 0; k < num_parts; ++k)
{
start = parts[k];
if (k == num_parts - 1)
{
end = num_points;
}
else
{
end = parts[k + 1];
}
mapnik::geometry::line_string<double> line;
line.reserve(end - start);
for (int j = start; j < end; ++j)
{
double x = record.read_double();
double y = record.read_double();
line.emplace_back(x, y);
}
multi_line.push_back(std::move(line));
}
geom = std::move(multi_line);
}
return geom;
}
mapnik::geometry::geometry<double> shape_io::read_polyline_parts(shape_file::record_type & record, std::vector<std::pair<int, int>> const& parts)
{
mapnik::geometry::geometry<double> geom; // default empty
int total_num_parts = record.read_ndr_integer();
int num_parts = parts.size();
mapnik::geometry::multi_line_string<double> multi_line;
multi_line.reserve(num_parts);
for (int k = 0; k < num_parts; ++k)
{
int start = parts[k].first;
int end = parts[k].second;
unsigned pos = 4 + 32 + 8 + 4 * total_num_parts + start * 16;
record.set_pos(pos);
mapnik::geometry::line_string<double> line;
line.reserve(end - start);
for (int j = start; j < end; ++j)
{
double x = record.read_double();
double y = record.read_double();
line.emplace_back(x, y);
}
multi_line.push_back(std::move(line));
}
geom = std::move(multi_line);
return geom;
}
mapnik::geometry::geometry<double> shape_io::read_polygon(shape_file::record_type & record)
{
mapnik::geometry::geometry<double> geom; // default empty
int num_parts = record.read_ndr_integer();
int num_points = record.read_ndr_integer();
std::vector<int> parts;
parts.resize(num_parts);
std::for_each(parts.begin(), parts.end(), [&](int & part) { part = record.read_ndr_integer();});
mapnik::geometry::polygon<double> poly;
mapnik::geometry::multi_polygon<double> multi_poly;
for (int k = 0; k < num_parts; ++k)
{
int start = parts[k];
int end;
if (k == num_parts - 1) end = num_points;
else end = parts[k + 1];
mapnik::geometry::linear_ring<double> ring;
ring.reserve(end - start);
for (int j = start; j < end; ++j)
{
double x = record.read_double();
double y = record.read_double();
ring.emplace_back(x, y);
}
if (k == 0)
{
poly.push_back(std::move(ring));
}
else if (mapnik::util::is_clockwise(ring))
{
multi_poly.emplace_back(std::move(poly));
poly.clear();
poly.push_back(std::move(ring));
}
else
{
poly.push_back(std::move(ring));
}
}
if (multi_poly.size() > 0) // multi
{
multi_poly.emplace_back(std::move(poly));
geom = std::move(multi_poly);
}
else
{
geom = std::move(poly);
}
mapnik::geometry::correct(geom);
return geom;
}
mapnik::geometry::geometry<double> shape_io::read_polygon_parts(shape_file::record_type & record, std::vector<std::pair<int,int>> const& parts)
{
mapnik::geometry::geometry<double> geom; // default empty
int total_num_parts = record.read_ndr_integer();
mapnik::geometry::polygon<double> poly;
mapnik::geometry::multi_polygon<double> multi_poly;
int num_parts = parts.size();
for (int k = 0; k < num_parts; ++k)
{
int start = parts[k].first;
int end = parts[k].second;
unsigned pos = 4 + 32 + 8 + 4 * total_num_parts + start * 16;
record.set_pos(pos);
mapnik::geometry::linear_ring<double> ring;
ring.reserve(end - start);
for (int j = start; j < end; ++j)
{
double x = record.read_double();
double y = record.read_double();
ring.emplace_back(x, y);
}
if (k == 0)
{
poly.push_back(std::move(ring));
}
else if (mapnik::util::is_clockwise(ring))
{
multi_poly.emplace_back(std::move(poly));
poly.clear();
poly.push_back(std::move(ring));
}
else
{
poly.push_back(std::move(ring));
}
}
if (multi_poly.size() > 0) // multi
{
multi_poly.emplace_back(std::move(poly));
geom = std::move(multi_poly);
}
else
{
geom = std::move(poly);
}
mapnik::geometry::correct(geom);
return geom;
}