Convert Oracle Spatial to MySQL Spatial

Oracle To Mysql Geometry Conversion.php

<?php

/**
 * Convert an Oracle SYS.SDO_GEOMETRY definition (perhaps extracted from an insert 
 * statement) to a MySQL Geometry column. This function only handles Polygons and 
 * Multipolygons.
 * 
 * Example:
 * $definition = "MDSYS.SDO_GEOMETRY(2003,4326,NULL,MDSYS.SDO_ELEM_INFO_ARRAY(1,1003,1),MDSYS.SDO_ORDINATE_ARRAY(-75.01703,41.79308,-75.02978,41.7941,-75.02735,41.772,-75.02716,41.77193,-75.02697,41.77187,-75.01354,41.79051,-75.01337,41.79061,-75.0132,41.79072,-75.00949,41.79234,-75.00946,41.79254,-75.00943,41.79274,-75.00518,41.7943,-74.9995,41.79178,-74.99365,41.79788,-74.99383,41.79798,-74.99876,41.80318,-74.9988,41.80337,-74.99883,41.80349,-75.00425,41.80479,-75.00431,41.80459,-75.01239,41.79415,-75.01245,41.79412,-75.01688,41.79345,-75.01696,41.79327,-75.01703,41.79308))";
 * $sql = "INSERT INTO mytable (geom) VALUES (".OraclePolygonToMysql($definition).")";
 */
function OraclePolygonToMysql($definition){
	// Get the geometry type, our data should only be polygons and multipolygons
	$SDO_GTYPE = substr($definition, strpos($definition, "(") + 3, 2);
	switch($SDO_GTYPE){
		case "03": $type = "POLYGON"; break;
		case "07": $type = "MULTIPOLYGON"; break;
		default: die("hol up i thought we only had polygons in this bitch");
	}

	// MDSYS.SDO_ELEM_INFO_ARRAY contains info about how to split up the coordinates..
	// So the info array is some dumb ass 1-indexed triplet model where we only need every third index..
	// https://docs.oracle.com/cd/B12037_01/appdev.101/b10826/sdo_objrelschema.htm#i1006226
	$start = strpos($definition, "MDSYS.SDO_ELEM_INFO_ARRAY")+strlen("MDSYS.SDO_ELEM_INFO_ARRAY(");
	$infoArray = explode(",", substr($definition, $start, strpos($definition, ")", $start) - $start));

	// MDSYS.SDO_ORDINATE_ARRAY contains the actual ordinates that need to be grouped properly for 
	// MySQL to understand them
	$start = strpos($definition, "MDSYS.SDO_ORDINATE_ARRAY") + strlen("MDSYS.SDO_ORDINATE_ARRAY");
	$ordsArray = explode(",",trim(substr($definition, $start), " ()")); 

	// Get the starting index fro each group
	$groupStarts = array();
	while(count($infoArray) > 0){
		$startIndex = intval(array_shift($infoArray)) - 1; // compensate for the dumb ass 1-index
		array_shift($infoArray); array_shift($infoArray); // we don't need these... i don't think
		$groupStarts[] = $startIndex;
	}

	// Get the ending index for each group
	$groups = array();
	for($i=0; $i<count($groupStarts); $i++){
		$start = $groupStarts[$i];
		$end = isset($groupStarts[$i+1]) ? $groupStarts[$i+1] - 1 : count($ordsArray)-1;
		$groups[] = array("first"=>$start, "len"=>$end-$start+1);
	}

	// Group the indexes into their own arrays
	for($i=0; $i<count($groups); $i++) 
		$groups[$i]['group'] = array_slice($ordsArray, $groups[$i]['first'], $groups[$i]['len']);

	// Create the string from the groups array
	$chunks = array();
	foreach($groups as $group){
		$chunked = array_chunk($group['group'], 2);
		foreach($chunked as $k=>$chnk) $chunked[$k] = implode(" ", $chnk);
		$c = "(".implode(",", $chunked).")";
		$chunks[] = $type === "MULTIPOLYGON" ? "($c)" : $c;
	}

	return "GeomFromText('$type(".implode(",",$chunks).")')";
}