GeoQuery

GeoQuery

/*
 * Copyright 2014 David Herges <david@spektrakel.de>
 * Licensed under MIT (http://opensource.org/licenses/MIT)
 */

define('M_NEGATIVE_PI_2', ((double) 0.0 - M_PI_2));
define('M_NEGATIVE_PI', ((double) 0.0 - M_PI));
define('M_2PI', ((double) 2.0 * M_PI));

/**
 * A Query to perform geolocation searches. Should be easy to adopt to other Frameworks than TYPO3
 *
 * <p>
 * All you need is (latitude, longitude, perimeter) -> (southEast, northWest) boundary?
 * Have a look at {@link #toRectangularBounds($latitude, $longitude, $perimeter)}!
 *
 * <p>
 * Lots of credits go to Jan Matuschek.
 *
 * @link http://janmatuschek.de/LatitudeLongitudeBoundingCoordinates
 */
class GeoQuery extends \TYPO3\CMS\Extbase\Persistence\Generic\Query {

    const PROPERTY_NAME_LATITUDE = "latitude";

    const PROPERTY_NAME_LONGITUDE = "longitude";

    /**
     * Radius of the Earth's surface in meters
     */
    const EARTH_RADIUS_METERS = 6371010;

    const MIN_LAT = M_NEGATIVE_PI_2; // Math.toRadians(-90d);  // -PI/2
    const MAX_LAT = M_PI_2;          // Math.toRadians(90d);   //  PI/2
    const MIN_LON = M_NEGATIVE_PI;   // Math.toRadians(-180d); // -PI
    const MAX_LON = M_PI;            // Math.toRadians(180d);  //  PI


    /**
     * Returns a constraint that filters entries whose geolocation is within the rectangular bounds of a plane surface
     * area around the center point (latitude, longitude) and within radius (perimeter) in meters.
     *
     * @param $latitude Latitude in degrees; floating-point value
     * @param $longitude Longitude in degrees; floating-point value
     * @param $perimeter Perimeter; integer value in meters
     *
     * @return \TYPO3\CMS\Extbase\Persistence\Generic\Qom\ConstraintInterface
     */
    public function around($latitude, $longitude, $perimeter) {
        // (lat, long, perimeter) to rectangular bounds
        $bounds = $this->toRectangularBounds($latitude, $longitude, $perimeter);

        // where condition: (lat >= minLat) && (lat <= maxLat) && (lon >= minLon) && (lon <= maxLon)
        return $this->logicalAnd(
            $this->greaterThanOrEqual(self::PROPERTY_NAME_LATITUDE, $bounds->minLat),
            $this->lessThanOrEqual(self::PROPERTY_NAME_LATITUDE, $bounds->maxLat),
            $this->greaterThanOrEqual(self::PROPERTY_NAME_LONGITUDE, $bounds->minLon),
            $this->lessThanOrEqual(self::PROPERTY_NAME_LONGITUDE, $bounds->maxLon)
        );
    }

    /**
     * Courtesy of http://janmatuschek.de/LatitudeLongitudeBoundingCoordinates
     *
     * @param $latitude
     * @param $longitude
     * @param $perimeter
     *
     * @return \stdClass With properties 'minLat', 'maxLat', 'minLon', 'maxLon'
     */
    private function toRectangularBounds($latitude, $longitude, $perimeter) {
        // degrees to radians
        $radLat = deg2rad($latitude);
        $radLon = deg2rad($longitude);
        $radDist = $perimeter / self::EARTH_RADIUS_METERS;

        // initial values for minLat, maxLat, minLon, maxLon
        $minLat = $radLat - $radDist;
        $maxLat = $radLat + $radDist;
        $minLon = (double) 0.0;
        $maxLon = (double) 0.0;

        if (($minLat > self::MIN_LAT) && ($maxLat < self::MAX_LAT)) {
            $deltaLon = asin(sin($radDist) / cos($radLat));
            $minLon = $radLon - $deltaLon;
            if ($minLon < self::MIN_LON) {
                $minLon += M_2PI;
            }
            $maxLon = $radLon + $deltaLon;
            if ($maxLon > self::MAX_LON) {
                $maxLon -= M_2PI;
            }
        } else {
            // a pole is within the distance
            $minLat = max($minLat, self::MIN_LAT);
            $maxLat = min($maxLat, self::MAX_LAT);
            $minLon = self::MIN_LON;
            $maxLon = self::MAX_LON;
        }

        $bounds = new \stdClass();
        $bounds->minLat = rad2deg($minLat);
        $bounds->maxLat = rad2deg($maxLat);
        $bounds->minLon = rad2deg($minLon);
        $bounds->maxLon = rad2deg($maxLon);

        return $bounds;
    }

}