app/Module/GeoDispersion/PlaceMappers/CoordinatesPlaceMapper.php
<?php
/**
* webtrees-lib: MyArtJaub library for webtrees
*
* @package MyArtJaub\Webtrees
* @subpackage GeoDispersion
* @author Jonathan Jaubart <dev@jaubart.com>
* @copyright Copyright (c) 2021-2022, Jonathan Jaubart
* @license http://www.gnu.org/licenses/gpl.html GNU General Public License, version 3
*/
declare(strict_types=1);
namespace MyArtJaub\Webtrees\Module\GeoDispersion\PlaceMappers;
use Brick\Geo\BoundingBox;
use Brick\Geo\Point;
use Brick\Geo\Engine\GeometryEngine;
use Brick\Geo\Engine\PDOEngine;
use Fisharebest\Webtrees\I18N;
use Fisharebest\Webtrees\Place;
use Fisharebest\Webtrees\PlaceLocation;
use Fisharebest\Webtrees\Registry;
use Illuminate\Database\Capsule\Manager as DB;
use MyArtJaub\Webtrees\Contracts\GeoDispersion\MapDefinitionInterface;
use MyArtJaub\Webtrees\Contracts\GeoDispersion\PlaceMapperInterface;
use Throwable;
/**
* Mapper using coordinated to map a location to a GeoJson map feature.
* This use the PlaceLocation table to determine the coordinates of the place, through the core PlaceLocation object.
*
* {@internal This mapper is indexing the features based on a grid to optimise the performances.
* Using the geospatial `contains` (SQL `ST_contains`) method naively is a lot slower.}
*/
class CoordinatesPlaceMapper implements PlaceMapperInterface
{
use PlaceMapperTrait;
private ?string $cache_key = null;
private ?GeometryEngine $geometry_engine = null;
/**
* {@inheritDoc}
* @see \MyArtJaub\Webtrees\Contracts\GeoDispersion\PlaceMapperInterface::title()
*/
public function title(): string
{
return I18N::translate('Mapping on place coordinates');
}
/**
* {@inheritDoc}
*
* {@internal The Place is associated to a Point only.
* PlaceLocation can calculate a BoundingBox.
* Using a BoundingBox could make the mapping more complex and potentially arbitary.
* Furthermore, when no coordinate is found for the place or its children, then it bubbles up to the parents.
* This could create the unwanted side effect of a very large area to consider}
*
* @see \MyArtJaub\Webtrees\Contracts\GeoDispersion\PlaceMapperInterface::map()
*/
public function map(Place $place, string $feature_property): ?string
{
$location = new PlaceLocation($place->gedcomName());
$longitude = $location->longitude();
$latitude = $location->latitude();
if ($longitude === null || $latitude === null) {
return null;
}
$features_index = $this->featuresIndex();
if ($features_index === null) {
return null;
}
$place_point = Point::xy($longitude, $latitude, $features_index['SRID']);
$grid_box = $this->getGridCell(
$place_point,
$features_index['map_NE'],
$features_index['map_SW'],
$features_index['nb_columns']
);
if ($grid_box === null || !$this->setGeometryEngine() || $this->geometry_engine == null) {
return null;
}
$features = $features_index['grid'][$grid_box[0]][$grid_box[1]];
foreach ($features as $feature) {
$geometry = $feature->getGeometry();
if (
$geometry !== null && $place_point->SRID() === $geometry->SRID() &&
$this->geometry_engine->contains($geometry, $place_point)
) {
return $feature->getProperty($feature_property);
}
}
return null;
}
/**
* Return the XY coordinates in a bounded grid of the cell containing a specific point.
*
* @param Point $point Point to find
* @param Point $grid_NE North-East point of the bounded grid
* @param Point $grid_SW South-West point fo the bounded grid
* @param int $grid_columns Number of columns/rows in the grid
* @return int[]|NULL
*/
protected function getGridCell(Point $point, Point $grid_NE, Point $grid_SW, int $grid_columns): ?array
{
list($x, $y) = $point->toArray();
list($x_max, $y_max) = $grid_NE->toArray();
list($x_min, $y_min) = $grid_SW->toArray();
$x_step = ($x_max - $x_min) / $grid_columns;
$y_step = ($y_max - $y_min) / $grid_columns;
if ($x_min <= $x && $x <= $x_max && $y_min <= $y && $y <= $y_max) {
return [
$x === $x_max ? $grid_columns - 1 : intval(($x - $x_min) / $x_step),
$y === $y_max ? $grid_columns - 1 : intval(($y - $y_min) / $y_step)
];
}
return null;
}
/**
* Get an indexed array of the features of the map.
*
* {@internal The map is divided in a grid, eacg cell containing the features which bounding box overlaps that cell.
* The grid is computed once for each map, and cached.}
*
* @phpcs:ignore Generic.Files.LineLength.TooLong
* @return array{grid: array<int, array<int, \Brick\Geo\IO\GeoJSON\Feature[]>>, nb_columns: int, map_NE: \Brick\Geo\Point, map_SW: \Brick\Geo\Point, SRID: int}|NULL
*/
protected function featuresIndex(): ?array
{
$cacheKey = $this->cacheKey();
if ($cacheKey === null) {
return null;
}
return Registry::cache()->array()->remember($cacheKey, function (): ?array {
$map_def = $this->data('map');
if (
!$this->setGeometryEngine()
|| $map_def === null
|| !($map_def instanceof MapDefinitionInterface)
) {
return null;
}
$bounding_boxes = [];
$map_bounding_box = new BoundingBox();
$srid = 0;
foreach ($map_def->features() as $feature) {
$geometry = $feature->getGeometry();
if ($geometry === null) {
continue;
}
$srid = $geometry->SRID();
$bounding_box = $geometry->getBoundingBox();
$bounding_boxes[] = [$feature, $bounding_box];
$map_bounding_box = $map_bounding_box->extendedWithBoundingBox($bounding_box);
}
$grid_columns = count($bounding_boxes);
$grid = array_fill(0, $grid_columns, array_fill(0, $grid_columns, []));
$map_NE = $map_bounding_box->getNorthEast();
$map_SW = $map_bounding_box->getSouthWest();
foreach ($bounding_boxes as $item) {
$grid_box_SW = $this->getGridCell($item[1]->getSouthWest(), $map_NE, $map_SW, $grid_columns) ?? [1, 1];
$grid_box_NE = $this->getGridCell($item[1]->getNorthEast(), $map_NE, $map_SW, $grid_columns) ?? [0, 0];
for ($i = $grid_box_SW[0]; $i <= $grid_box_NE[0]; $i++) {
for ($j = $grid_box_SW[1]; $j <= $grid_box_NE[1]; $j++) {
$grid[$i][$j][] = $item[0];
}
}
}
return [
'grid' => $grid,
'nb_columns' => $grid_columns,
'map_NE' => $map_NE,
'map_SW' => $map_SW,
'SRID' => $srid
];
});
}
/**
* Set the Brick Geo Engine to use the database for geospatial computations.
* The engine is set only if it has not been set beforehand.
*
* @return bool
*/
protected function setGeometryEngine(): bool
{
try {
if ($this->geometry_engine === null) {
$this->geometry_engine = new PDOEngine(DB::connection()->getPdo());
}
$point = Point::xy(1, 1);
return $this->geometry_engine->equals($point, $point);
} catch (Throwable $ex) {
}
return false;
}
/**
* Get the key to cache the indexed grid of features.
*
* @return string|NULL
*/
protected function cacheKey(): ?string
{
if ($this->cache_key === null) {
$map_def = $this->data('map');
if ($map_def === null || !($map_def instanceof MapDefinitionInterface)) {
return null;
}
return spl_object_id($this) . '-map-' . $map_def->id();
}
return $this->cache_key;
}
}