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lots of refactoring -- streamlined wkb -> geojson types [no ci]
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@program--
program-- committed Apr 29, 2023
1 parent 1eb76fd commit ed7e22f
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Showing 4 changed files with 245 additions and 183 deletions.
167 changes: 144 additions & 23 deletions include/geopackage/GeoPackage.hpp
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Original file line number Diff line number Diff line change
@@ -1,18 +1,28 @@
#ifndef NGEN_GEOPACKAGE_H
#define NGEN_GEOPACKAGE_H

#include <boost/geometry/srs/projections/epsg_params.hpp>
#include <memory>
#include <numeric>
#include <stdexcept>
#include <string>
#include <vector>
#include <sqlite3.h>

#include "SQLite.hpp"
#include <boost/geometry/srs/transformation.hpp>
#include <boost/geometry/srs/epsg.hpp>

#include "FeatureCollection.hpp"

#include "JSONGeometry.hpp"
#include "SQLite.hpp"
#include "features/CollectionFeature.hpp"
#include "wkb/reader.hpp"

namespace bsrs = boost::geometry::srs;

namespace geopackage {

namespace {
inline const geojson::FeatureType feature_type_map(const std::string& g)
{
if (g == "POINT") return geojson::FeatureType::Point;
Expand All @@ -23,30 +33,66 @@ inline const geojson::FeatureType feature_type_map(const std::string& g)
if (g == "MULTIPOLYGON") return geojson::FeatureType::MultiPolygon;
return geojson::FeatureType::GeometryCollection;
}
} // anonymous namespace

inline geojson::geometry build_geometry(const sqlite_iter& row, const geojson::FeatureType geom_type, const std::string& geom_col)
{
const std::vector<uint8_t> geometry_blob = row.get<std::vector<uint8_t>>(geom_col);
int index = 0;
if (geometry_blob[0] != 'G' && geometry_blob[1] != 'P') {
throw std::runtime_error("expected geopackage WKB, but found invalid format instead");
}
index += 2;

// skip version
index++;

geojson::geometry geometry;
// flags
const bool is_extended = geometry_blob[index] & 0x00100000;
const bool is_empty = geometry_blob[index] & 0x00010000;
const uint8_t indicator = (geometry_blob[index] & 0x00001110) >> 1;
const uint8_t endian = geometry_blob[index] & 0x00000001;
index++;

switch(geom_type) {
case geojson::FeatureType::Point:
break;
case geojson::FeatureType::LineString:
break;
case geojson::FeatureType::Polygon:
break;
case geojson::FeatureType::MultiPoint:
break;
case geojson::FeatureType::MultiLineString:
break;
case geojson::FeatureType::MultiPolygon:
break;
case geojson::FeatureType::GeometryCollection:
break;
default:
break;
// Read srs_id
uint32_t srs_id;
wkb::copy_from(geometry_blob, index, srs_id, endian);

std::vector<double> envelope; // may be unused
if (indicator > 0 & indicator < 5) {
// not an empty envelope

envelope.resize(4); // only 4, not supporting Z or M dims
wkb::copy_from(geometry_blob, index, envelope[0], endian);
wkb::copy_from(geometry_blob, index, envelope[1], endian);
wkb::copy_from(geometry_blob, index, envelope[2], endian);
wkb::copy_from(geometry_blob, index, envelope[3], endian);

// ensure `index` is at beginning of data
if (indicator == 2 || indicator == 3) {
index += 2 * sizeof(double);
} else if (indicator == 4) {
index += 4 * sizeof(double);
}
}

const std::vector<uint8_t> geometry_data(geometry_blob.begin() + index, geometry_blob.end());
geojson::geometry geometry = wkb::read_wkb(geometry_data);

if (srs_id != 4326) {
return geometry;
} else {
geojson::geometry projected;

// project coordinates from whatever they are to 4326
boost::geometry::srs::transformation<> tr{
bsrs::epsg(srs_id),
bsrs::epsg(4326)
};

tr.forward(geometry, projected);

return projected;
}
}

Expand Down Expand Up @@ -101,9 +147,84 @@ inline geojson::Feature build_feature(
const std::string& geom_col
)
{
const auto type = feature_type_map(geom_type);
const geojson::PropertyMap properties = build_properties(row, geom_col);
const geojson::geometry geometry = build_geometry(row, type, geom_col);
const auto type = feature_type_map(geom_type);
const auto id = row.get<std::string>("id");
std::vector<double> bounding_box = {0, 0, 0, 0}; // TODO
geojson::PropertyMap properties = std::move(build_properties(row, geom_col));
geojson::geometry geometry = std::move(build_geometry(row, type, geom_col));

switch(type) {
case geojson::FeatureType::Point:
return std::make_shared<geojson::PointFeature>(geojson::PointFeature(
boost::get<geojson::coordinate_t>(geometry),
id,
properties,
bounding_box,
std::vector<geojson::FeatureBase*>(),
std::vector<geojson::FeatureBase*>(),
{}
));
case geojson::FeatureType::LineString:
return std::make_shared<geojson::LineStringFeature>(geojson::LineStringFeature(
boost::get<geojson::linestring_t>(geometry),
id,
properties,
bounding_box,
std::vector<geojson::FeatureBase*>(),
std::vector<geojson::FeatureBase*>(),
{}
));
case geojson::FeatureType::Polygon:
return std::make_shared<geojson::PolygonFeature>(geojson::PolygonFeature(
boost::get<geojson::polygon_t>(geometry),
id,
properties,
bounding_box,
std::vector<geojson::FeatureBase*>(),
std::vector<geojson::FeatureBase*>(),
{}
));
case geojson::FeatureType::MultiPoint:
return std::make_shared<geojson::MultiPointFeature>(geojson::MultiPointFeature(
boost::get<geojson::multipoint_t>(geometry),
id,
properties,
bounding_box,
std::vector<geojson::FeatureBase*>(),
std::vector<geojson::FeatureBase*>(),
{}
));
case geojson::FeatureType::MultiLineString:
return std::make_shared<geojson::MultiLineStringFeature>(geojson::MultiLineStringFeature(
boost::get<geojson::multilinestring_t>(geometry),
id,
properties,
bounding_box,
std::vector<geojson::FeatureBase*>(),
std::vector<geojson::FeatureBase*>(),
{}
));
case geojson::FeatureType::MultiPolygon:
return std::make_shared<geojson::MultiPolygonFeature>(geojson::MultiPolygonFeature(
boost::get<geojson::multipolygon_t>(geometry),
id,
properties,
bounding_box,
std::vector<geojson::FeatureBase*>(),
std::vector<geojson::FeatureBase*>(),
{}
));
default:
return std::make_shared<geojson::CollectionFeature>(geojson::CollectionFeature(
std::vector<geojson::geometry>{geometry},
id,
properties,
bounding_box,
std::vector<geojson::FeatureBase*>(),
std::vector<geojson::FeatureBase*>(),
{}
));
}
};

inline std::shared_ptr<geojson::FeatureCollection> read(const std::string& gpkg_path, const std::string& layer = "", const std::vector<std::string>& ids = {})
Expand Down
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