ถาม google map การวัดระยะทางจากจุดสองจุด กับ เส้นทางการเดินทาง

<?php

header("Content-type: text/xml");
require("db.php");
function parseToXML($htmlStr)

{

$xmlStr=str_replace('<','&lt;',$htmlStr);

$xmlStr=str_replace('>','&gt;',$xmlStr);

$xmlStr=str_replace('"','&quot;',$xmlStr);

$xmlStr=str_replace("'",'&#39;',$xmlStr);

$xmlStr=str_replace("&",'&amp;',$xmlStr);

return $xmlStr;

}

 

// Get parameters from URL

$center_lat = $_GET["latitude"];

$center_lng = $_GET["longitude"];

$radius = $_GET["radius"];

// Opens a connection to a MySQL server

$connection=mysql_connect (localhost, $username, $password);

if (!$connection) {

die('Not connected : ' . mysql_error());

}

/ Set the active MySQL database

$db_selected = mysql_select_db($database, $connection);

if (!$db_selected) {

die ('Can\'t use db : ' . mysql_error());

}


// Select all the rows in the markers table

$query = sprintf("SELECT  latitude, longitude, ( 3959 * acos( cos( radians('%s') ) * cos( radians( latitude ) ) * cos( radians( longitude ) - radians('%s') ) + sin( radians('%s') ) * sin( radians( latitude ) ) ) ) AS distance FROM place HAVING distance < '%s' ORDER BY distance LIMIT 0 , 20",

mysql_real_escape_string($center_lat),

mysql_real_escape_string($center_lng),
.
mysql_real_escape_string($center_lat),

mysql_real_escape_string($radius));

 
$result = mysql_query($query);
if (!$result) {

die('Invalid query: ' . mysql_error());
.
}

 

// Start XML file, echo parent node
echo "<markers>\n";

// Iterate through the rows, printing XML nodes for each

while ($row = @mysql_fetch_assoc($result)){

// ADD TO XML DOCUMENT NODE

echo '<marker ';

echo 'name_place="' . parseToXML($row['name_place']) . '" ';
echo 'latitude="' . $row['latitude'] . '" ';
echo 'longitude="' . $row['longitude'] . '" ';
echo 'distance="' . $row['distance'] . '" ';

echo "/>\n";
}
// End XML file
echo "</markers>\n";

?>