pathing.example.php

<?php

require('pathing.php');

$gmap = array(
    array(6, 5, 6, 4, 6, 1, 2, 6, 9, 6, 6, 5, 6, 4, 6, 1, 2, 6, 9, 6),
    array(8, 5, 3, 2, 9, 9, 3, 2, 4, 7, 8, 5, 3, 2, 9, 9, 3, 2, 4, 7),
    array(4, 8, 7, 7, 3, 5, 2, 8, 3, 5, 4, 8, 7, 7, 3, 5, 2, 8, 3, 5),
    array(7, 5, 5, 8, 7, 7, 8, 4, 8, 5, 7, 5, 5, 8, 7, 7, 8, 4, 8, 5),
    array(4, 5, 1, 6, 4, 6, 9, 3, 8, 1, 4, 5, 1, 6, 4, 6, 9, 3, 8, 1),
    array(4, 6, 6, 4, 2, 7, 8, 8, 2, 2, 4, 6, 6, 4, 2, 7, 8, 8, 2, 2),
    array(9, 4, 4, 5, 8, 4, 9, 5, 5, 2, 9, 4, 4, 5, 8, 4, 9, 5, 5, 2),
    array(2, 9, 4, 9, 4, 8, 4, 1, 4, 6, 2, 9, 4, 9, 4, 8, 4, 1, 4, 6),
    array(5, 8, 1, 2, 2, 2, 9, 1, 6, 9, 5, 8, 1, 2, 2, 2, 9, 1, 6, 9),
    array(8, 9, 2, 7, 5, 1, 2, 9, 8, 9, 8, 9, 2, 7, 5, 1, 2, 9, 8, 9),
    array(6, 5, 6, 4, 6, 1, 2, 6, 9, 6, 6, 5, 6, 4, 6, 1, 2, 6, 9, 6),
    array(8, 5, 3, 2, 9, 9, 3, 2, 4, 7, 8, 5, 3, 2, 9, 9, 3, 2, 4, 7),
    array(4, 8, 7, 7, 3, 5, 2, 8, 3, 5, 4, 8, 7, 7, 3, 5, 2, 8, 3, 5),
    array(7, 5, 5, 8, 7, 7, 8, 4, 8, 5, 7, 5, 5, 8, 7, 7, 8, 4, 8, 5),
    array(4, 5, 1, 6, 4, 6, 9, 3, 8, 1, 4, 5, 1, 6, 4, 6, 9, 3, 8, 1),
    array(4, 6, 6, 4, 2, 7, 8, 8, 2, 2, 4, 6, 6, 4, 2, 7, 8, 8, 2, 2),
    array(9, 4, 4, 5, 8, 4, 9, 5, 5, 2, 9, 4, 4, 5, 8, 4, 9, 5, 5, 2),
    array(2, 9, 4, 9, 4, 8, 4, 1, 4, 6, 2, 9, 4, 9, 4, 8, 4, 1, 4, 6),
    array(5, 8, 1, 2, 2, 2, 9, 1, 6, 9, 5, 8, 1, 2, 2, 2, 9, 1, 6, 9),
    array(8, 9, 2, 7, 5, 1, 2, 9, 8, 9, 8, 9, 2, 7, 5, 1, 2, 9, 8, 9),
    array(6, 5, 6, 4, 6, 1, 2, 6, 9, 6, 6, 5, 6, 4, 6, 1, 2, 6, 9, 6),
    array(8, 5, 3, 2, 9, 9, 3, 2, 4, 7, 8, 5, 3, 2, 9, 9, 3, 2, 4, 7),
    array(4, 8, 7, 7, 3, 5, 2, 8, 3, 5, 4, 8, 7, 7, 3, 5, 2, 8, 3, 5),
    array(7, 5, 5, 8, 7, 7, 8, 4, 8, 5, 7, 5, 5, 8, 7, 7, 8, 4, 8, 5),
    array(4, 5, 1, 6, 4, 6, 9, 3, 8, 1, 4, 5, 1, 6, 4, 6, 9, 3, 8, 1),
    array(4, 6, 6, 4, 2, 7, 8, 8, 2, 2, 4, 6, 6, 4, 2, 7, 8, 8, 2, 2),
    array(9, 4, 4, 5, 8, 4, 9, 5, 5, 2, 9, 4, 4, 5, 8, 4, 9, 5, 5, 2),
    array(2, 9, 4, 9, 4, 8, 4, 1, 4, 6, 2, 9, 4, 9, 4, 8, 4, 1, 4, 6),
    array(5, 8, 1, 2, 2, 2, 9, 1, 6, 9, 5, 8, 1, 2, 2, 2, 9, 1, 6, 9),
    array(8, 9, 2, 7, 5, 1, 2, 9, 8, 9, 8, 9, 2, 7, 5, 1, 2, 9, 8, 9),
    array(6, 5, 6, 4, 6, 1, 2, 6, 9, 6, 6, 5, 6, 4, 6, 1, 2, 6, 9, 6),
    array(8, 5, 3, 2, 9, 9, 3, 2, 4, 7, 8, 5, 3, 2, 9, 9, 3, 2, 4, 7),
    array(4, 8, 7, 7, 3, 5, 2, 8, 3, 5, 4, 8, 7, 7, 3, 5, 2, 8, 3, 5),
    array(7, 5, 5, 8, 7, 7, 8, 4, 8, 5, 7, 5, 5, 8, 7, 7, 8, 4, 8, 5),
    array(4, 5, 1, 6, 4, 6, 9, 3, 8, 1, 4, 5, 1, 6, 4, 6, 9, 3, 8, 1),
    array(4, 6, 6, 4, 2, 7, 8, 8, 2, 2, 4, 6, 6, 4, 2, 7, 8, 8, 2, 2),
    array(9, 4, 4, 5, 8, 4, 9, 5, 5, 2, 9, 4, 4, 5, 8, 4, 9, 5, 5, 2),
    array(2, 9, 4, 9, 4, 8, 4, 1, 4, 6, 2, 9, 4, 9, 4, 8, 4, 1, 4, 6),
    array(5, 8, 1, 2, 2, 2, 9, 1, 6, 9, 5, 8, 1, 2, 2, 2, 9, 1, 6, 9),
    array(8, 9, 2, 7, 5, 1, 2, 9, 8, 9, 8, 9, 2, 7, 5, 1, 2, 9, 8, 9),
);

$map = $queue = $visited = array();
$result = findLowest(array(0, 0, 19, 39), $gmap);

print_r($result);

pathing.php

<?php

/**
 * A* implementation.
 *
 * PHP version 5
 *
 * @category Algorithms
 * @package  Astar
 * @author   Tobias Sjösten <tobias.sjosten@gmail.com>
 * @license  http://www.gnu.org/licenses/gpl.html GNU License
 * @link     http://vvv.tobiassjosten.net/
 */

/**
 * Calculate the cheapest path between two points in a map.
 *
 * @param array $endpoints Start and end positions.
 * @param array $map       Grid to calculate path within.
 *
 * @return Array with keys 0=>cost and 1=>path from $start to $end.
 */
function findLowest($endpoints, $map)
{
    $queue = $visited = array();

    // Add start position to queue.
    $queue[$endpoints[0].'x'.$endpoints[1]] = array(
        array($endpoints[0], $endpoints[1]),
        true,
        $map[$endpoints[1]][$endpoints[0]]
    );

    while (true) {
        /* START FETCH ITEM */
        if (!count($queue)) {
            return false;
        }

        $cost = INF;
        $next_item = false;

        foreach ($queue as $item) {
            if ($item[2] < $cost) {
                $next_item = $item;
                $cost = $item[2];
            }
        }

        unset($queue[$next_item[0][0].'x'.$next_item[0][1]]);

        if (!$next_item) {
            break;
        }
        $item = $next_item;
        /* END FETCH ITEM */

        $item_id = $item[0][0].'x'.$item[0][1];
        if (!empty($visited[$item_id])) {
            continue;
        }
        $visited[$item_id] = $item[1];

        // If current node is the end node, we've found our path!
        if ($item[0][0] == $endpoints[2] && $item[0][1] == $endpoints[3]) {
            $path = array();
            $cost = 0;
            $node = $item[0];

            while ($parent = $visited[$node[0].'x'.$node[1]]) {
                $cost += $path[] = $map[$node[1]][$node[0]];

                if ($parent === true) {
                    break;
                }

                $node = $parent;
            }

            return array($cost, array_reverse($path));
        }

        /* START QUEUE ADJACENTS */
        $directions = array(array(0, -1), array(1, 0), array(0, 1), array(-1, 0));

        foreach ($directions as $direction) {
            $adjacent = array(
                $item[0][0] + $direction[0],
                $item[0][1] + $direction[1]
            );

            $in_range = !empty($map[$adjacent[1]])
                && !empty($map[$adjacent[1]][$adjacent[0]]);

            if (!empty($visited[$adjacent[0].'x'.$adjacent[1]]) || !$in_range) {
                continue;
            }

            /* START QUEUE ADD */
            $adjacent_id = $adjacent[0].'x'.$adjacent[1];
            $adjacent_cost = $item[2] + $map[$adjacent[1]][$adjacent[0]];

            $adjacent_queue = true;

            if (!empty($visited[$adjacent_id])) {
                $adjacent_queue = false;
            }

            if (!empty($queue[$adjacent_id])) {
                if ($adjacent_cost < $queue[$adjacent_id][2]) {
                    $queue[$adjacent_id][1] = true;
                    $queue[$adjacent_id][2] = $adjacent_cost;
                }

                $adjacent_queue = false;
            }

            if ($adjacent_queue) {
                $queue[$adjacent_id] = array($adjacent, $item[0], $adjacent_cost);
            }
            /* END QUEUE ADD */
        }
        /* END QUEUE ADJACENTS */
    }
}

thank you

Any time. :)