protected function getBoundingCoordinates(MapLocationValue $location, $distance)
{
$radiansLatitude = deg2rad($location->latitude);
$radiansLongitude = deg2rad($location->longitude);
$angularDistance = $distance / self::EARTH_RADIUS;
$deltaLongitude = asin(sin($angularDistance) / cos($radiansLatitude));
$lowLatitudeRadians = $radiansLatitude - $angularDistance;
$highLatitudeRadians = $radiansLatitude + $angularDistance;
// Check that bounding box does not include poles.
if ($lowLatitudeRadians > -M_PI_2 && $highLatitudeRadians < M_PI_2) {
$boundingCoordinates = array('lowLatitude' => rad2deg($lowLatitudeRadians), 'lowLongitude' => rad2deg($radiansLongitude - $deltaLongitude), 'highLatitude' => rad2deg($highLatitudeRadians), 'highLongitude' => rad2deg($radiansLongitude + $deltaLongitude));
} else {
// Handle the pole(s) being inside a bounding box, in this case we MUST cover
// full circle of Earth's longitude and one or both poles.
// Note that calculation for distances over the polar regions with flat Earth formula
// will be VERY imprecise.
$boundingCoordinates = array('lowLatitude' => rad2deg(max($lowLatitudeRadians, -M_PI_2)), 'lowLongitude' => rad2deg(-M_PI), 'highLatitude' => rad2deg(min($highLatitudeRadians, M_PI_2)), 'highLongitude' => rad2deg(M_PI));
}
return $boundingCoordinates;
}
