<?php

function p($x,$y){ return Array('x'=>$x,'y'=>$y); }

$points=Array(
    p(-8940.48,-51.5397),
    p(-8818.05,-69.5144),
    p(-8991.14,-250.521),
    p(-8795.79,-79.0435),
    p(-8829.54,-98.7120),
    p(-8786.79,-154.691),
    p(-8969.07,-80.9248),
    p(-8932.77,-274.706),
    p(-8980.23,-70.8425),
    p(-8858.29,-83.8734)
);

function shorter_distance(&$points){
    $shorted=Array();

    //I'll go ahead and say the first point is the starting point.
    //no need to make this crazy complicated
    $curpoint=array_shift($points);
    $shorted[]=$curpoint;

    while(!empty($points)) {
        $addpoint=0;
        $min_d=$d=0;
        foreach($points as $k=>$v){
            if($min_d||$min_d<($d=dist($v,$curpoint))) {
                $min_d=$d;
                $addpoint=$k;
            }
        }
        $shorted[]=$points[$addpoint];
        array_splice($points,$addpoint);
    }

    $points=$shorted;
}

function compute_travel_distance($points){
    $distance=0;
    for($x=1;$x<count($points);$x++) {
        $distance+=dist($points[$x],$points[$x-1]);
    }
    return $distance;
}

function dist($p1,$p2){
    return sqrt(pow($p1['x']-$p2['x'],2)+pow($p1['y']-$p2['y'],2));
}


echo "Travel distance before: ".compute_travel_distance($points)."\n";
shorter_distance($points);
echo "Travel distance after: ".compute_travel_distance($points)."\n";


?>