Baidu map coordinates, Google coordinates and Tencent coordinates are mutually transformed

<?php
// China Normal GCJ02 coordinate ----> Baidu Maps BD09 coordinate 
function Convert_GCJ02_To_BD09($lat,$lng){

    $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 array('lng'=>$lng,'lat'=>$lat);

}
// Baidu Maps BD09 coordinate ----> China Normal GCJ02 coordinate 

// Tencent maps also use GCJ02 coordinate 
function Convert_BD09_To_GCJ02($lat,$lng){

    $x_pi = 3.14159265358979324 * 3000.0 / 180.0;

    $x = $lng - 0.0065;

    $y = $lat - 0.006;

    $z = sqrt($x * $x + $y * $y) - 0.00002 * sin($y * $x_pi);

    $theta = atan2($y, $x) - 0.000003 * cos($x * $x_pi);

    $lng = $z * cos($theta);

    $lat = $z * sin($theta);

    return array('lng'=>$lng,'lat'=>$lat);

}

?>