/**
* Calculate the bounds corresponding to a specific center and zoom level for a give map size in pixels
* @param LatLng $center
* @param integer $zoom
* @param integer $width
* @param integer $height
* @return LatLngBounds
*/
public static function getBoundsFromCenterAndZoom(LatLng $center, $zoom, $width, $height = null)
{
if (is_null($height)) {
$height = $width;
}
$centerLat = $center->getLat();
$centerLng = $center->getLng();
$pix = LatLng::latToPixels($centerLat, $zoom);
$neLat = LatLng::pixelsToLat($pix - round(($height - 1) / 2), $zoom);
$swLat = LatLng::pixelsToLat($pix + round(($height - 1) / 2), $zoom);
$pix = LatLng::lngToPixels($centerLng, $zoom);
$swLng = LatLng::pixelsToLng($pix - round(($width - 1) / 2), $zoom);
$neLng = LatLng::pixelsToLng($pix + round(($width - 1) / 2), $zoom);
return new self(['southWest' => new LatLng(['lat' => $swLat, 'lng' => $swLng]), 'northEast' => new LatLng(['lat' => $neLat, 'lng' => $neLng])]);
}
/**
* Exact distance with Haversine formula
*
* @param LatLng $coord
*
* @return float
* @see http://www.movable-type.co.uk/scripts/latlong.html
*/
public function exactDistanceFrom(LatLng $coord)
{
$lat1 = deg2rad($this->getLat());
$lat2 = deg2rad($coord->getLat());
$lon1 = deg2rad($this->getLng());
$lon2 = deg2rad($coord->getLng());
$dLatHalf = ($lat2 - $lat1) / 2;
$dLonHalf = ($lon2 - $lon1) / 2;
$a = pow(sin($dLatHalf), 2) + cos($lat1) * cos($lat2) * pow(sin($dLonHalf), 2);
$c = 2 * atan2(sqrt($a), sqrt(1 - $a));
return $c * UnitsType::EARTH_RADIUS;
}