腾讯地图坐标转换为百度地图坐标

/**
	 * 腾讯地图坐标转换为百度地图坐标
	 */
	function convertQtB ($lat, $lng)
	{
		if (empty($lat) && empty($lng)) {
			return false;
		}

		$x_pi  = 3.14159265358979324 * 3000.0 / 180.0;
		$x     = $lng;
		$y     = $lat;
		$z     = sqrt($x * $x + $y * $y) + 0.00002 * sin($y * $x_pi);
		$theta = atan2($y, $x) + 0.000003 * cos($x * $x_pi);
		$lng   = $z * cos($theta) + 0.0065;
		$lat   = $z * sin($theta) + 0.006;

		return ['lat' => $lat, 'lng' => $lng];
	}