mapnik/plugins/input/shape/shape_featureset.cpp
2024-07-22 10:20:47 +01:00

172 lines
6 KiB
C++

/*****************************************************************************
*
* This file is part of Mapnik (c++ mapping toolkit)
*
* Copyright (C) 2024 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
*
*****************************************************************************/
// stl
#include <iostream>
#include <cassert>
// mapnik
#include <mapnik/debug.hpp>
#include <mapnik/feature_factory.hpp>
#include <mapnik/unicode.hpp>
// boost
#include "shape_featureset.hpp"
#include "shape_utils.hpp"
using mapnik::context_ptr;
using mapnik::feature_factory;
template<typename filterT>
shape_featureset<filterT>::shape_featureset(filterT const& filter,
std::string const& shape_name,
std::set<std::string> const& attribute_names,
std::string const& encoding,
int row_limit)
: filter_(filter)
, shape_(shape_name, false)
, query_ext_()
, feature_bbox_()
, tr_(new transcoder(encoding))
, shx_file_length_(0)
, row_limit_(row_limit)
, count_(0)
, ctx_(std::make_shared<mapnik::context_type>())
{
if (!shape_.shx().is_open())
{
throw mapnik::datasource_exception("Shape Plugin: can't open '" + shape_name + ".shx' file");
}
shape_file::record_type shx_header(100);
shape_.shx().read_record(shx_header);
shx_header.skip(6 * 4);
shx_file_length_ = shx_header.read_xdr_integer();
setup_attributes(ctx_, attribute_names, shape_name, shape_, attr_ids_);
}
template<typename filterT>
feature_ptr shape_featureset<filterT>::next()
{
if (row_limit_ && count_ >= row_limit_)
{
return feature_ptr();
}
std::streampos position_limit = 2 * shx_file_length_ - 2 * sizeof(int);
while (shape_.shx().is_good() && shape_.shx().pos() <= position_limit)
{
int offset = shape_.shx().read_xdr_integer();
int record_length = shape_.shx().read_xdr_integer();
shape_.move_to(2 * offset);
mapnik::value_integer feature_id = shape_.id();
assert(record_length == shape_.reclength_);
shape_file::record_type record(record_length * 2);
shape_.shp().read_record(record);
int type = record.read_ndr_integer();
// skip null shapes
if (type == shape_io::shape_null)
continue;
feature_ptr feature(feature_factory::create(ctx_, feature_id));
switch (type)
{
case shape_io::shape_point:
case shape_io::shape_pointm:
case shape_io::shape_pointz: {
double x = record.read_double();
double y = record.read_double();
if (!filter_.pass(mapnik::box2d<double>(x, y, x, y)))
continue;
feature->set_geometry(mapnik::geometry::point<double>(x, y));
break;
}
case shape_io::shape_multipoint:
case shape_io::shape_multipointm:
case shape_io::shape_multipointz: {
shape_io::read_bbox(record, feature_bbox_);
if (!filter_.pass(feature_bbox_))
continue;
int num_points = record.read_ndr_integer();
mapnik::geometry::multi_point<double> multi_point;
for (int i = 0; i < num_points; ++i)
{
double x = record.read_double();
double y = record.read_double();
multi_point.emplace_back(mapnik::geometry::point<double>(x, y));
}
feature->set_geometry(std::move(multi_point));
break;
}
case shape_io::shape_polyline:
case shape_io::shape_polylinem:
case shape_io::shape_polylinez: {
shape_io::read_bbox(record, feature_bbox_);
if (!filter_.pass(feature_bbox_))
continue;
feature->set_geometry(shape_io::read_polyline(record));
break;
}
case shape_io::shape_polygon:
case shape_io::shape_polygonm:
case shape_io::shape_polygonz: {
shape_io::read_bbox(record, feature_bbox_);
if (!filter_.pass(feature_bbox_))
continue;
feature->set_geometry(shape_io::read_polygon(record));
break;
}
default:
MAPNIK_LOG_DEBUG(shape) << "shape_featureset: Unsupported type" << type;
return feature_ptr();
}
if (attr_ids_.size())
{
shape_.dbf().move_to(shape_.id_);
try
{
for (auto id : attr_ids_)
{
shape_.dbf().add_attribute(id, *tr_, *feature); // TODO optimize!!!
}
}
catch (...)
{
MAPNIK_LOG_ERROR(shape) << "Shape Plugin: error processing attributes";
}
}
++count_;
return feature;
}
MAPNIK_LOG_DEBUG(shape) << "shape_featureset: Total shapes read=" << count_;
return feature_ptr();
}
template<typename filterT>
shape_featureset<filterT>::~shape_featureset()
{}
template class shape_featureset<mapnik::filter_in_box>;
template class shape_featureset<mapnik::filter_at_point>;