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radar-wp-custom/vendor/phayes/geophp/lib/adapters/EWKB.class.php

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2015-02-24 16:25:12 +01:00
<?php
/**
* EWKB (Extended Well Known Binary) Adapter
*/
class EWKB extends WKB
{
/**
* Read WKB binary string into geometry objects
*
* @param string $wkb An Extended-WKB binary string
*
* @return Geometry
*/
public function read($wkb, $is_hex_string = FALSE) {
if ($is_hex_string) {
$wkb = pack('H*',$wkb);
}
// Open the wkb up in memory so we can examine the SRID
$mem = fopen('php://memory', 'r+');
fwrite($mem, $wkb);
fseek($mem, 0);
$base_info = unpack("corder/ctype/cz/cm/cs", fread($mem, 5));
if ($base_info['s']) {
$srid = current(unpack("Lsrid", fread($mem, 4)));
}
else {
$srid = NULL;
}
fclose($mem);
// Run the wkb through the normal WKB reader to get the geometry
$wkb_reader = new WKB();
$geom = $wkb_reader->read($wkb);
// If there is an SRID, add it to the geometry
if ($srid) {
$geom->setSRID($srid);
}
return $geom;
}
/**
* Serialize geometries into an EWKB binary string.
*
* @param Geometry $geometry
*
* @return string The Extended-WKB binary string representation of the input geometries
*/
public function write(Geometry $geometry, $write_as_hex = FALSE) {
// We always write into NDR (little endian)
$wkb = pack('c',1);
switch ($geometry->getGeomType()) {
case 'Point';
$wkb .= pack('L',1);
$wkb .= $this->writePoint($geometry);
break;
case 'LineString';
$wkb .= pack('L',2);
$wkb .= $this->writeLineString($geometry);
break;
case 'Polygon';
$wkb .= pack('L',3);
$wkb .= $this->writePolygon($geometry);
break;
case 'MultiPoint';
$wkb .= pack('L',4);
$wkb .= $this->writeMulti($geometry);
break;
case 'MultiLineString';
$wkb .= pack('L',5);
$wkb .= $this->writeMulti($geometry);
break;
case 'MultiPolygon';
$wkb .= pack('L',6);
$wkb .= $this->writeMulti($geometry);
break;
case 'GeometryCollection';
$wkb .= pack('L',7);
$wkb .= $this->writeMulti($geometry);
break;
}
if ($write_as_hex) {
$unpacked = unpack('H*',$wkb);
return $unpacked[1];
}
else {
return $wkb;
}
}
}