Polygon::polygon_finder_recursive PHP Method

    function polygon_finder_recursive(Graph $graph, $currentPolygon, $currentVertex, $lastVertex)
    {
        // Interdiction path table
        // Struct : array[ pointGuid1 ][ pointGuid2 ]
        static $pathTable = array();
        $polygons = array();
        $return = false;
        $vertices = $graph->vertices;
        $edges = $graph->edges;
        if (is_null($lastVertex) || !isset($pathTable[$lastVertex->guid][$currentVertex->guid])) {
            // The path loops = area found
            if (in_array($currentVertex, $currentPolygon)) {
                // Working backward to find the closure point, exclude non-area included vertices
                $polygon = new Polygon();
                do {
                    $newPoint = array_pop($currentPolygon);
                    $polygon->addPoint($newPoint);
                } while ($currentVertex != $newPoint);
                $currentPolygon = $polygon;
                // If the polygon area doesn't include the central point
                if ($polygon->includes(reset($vertices)) !== 1) {
                    // Update the interdiction table
                    $j = count($currentPolygon) - 1;
                    for ($k = 0; $k < count($currentPolygon); $k++) {
                        //$pathTable[ $currentPolygon[ $j ]->guid ][ $currentPolygon[ $k ]->guid ] = true;
                        $pathTable[$currentPolygon[$k]->guid][$currentPolygon[$j]->guid] = true;
                        $j++;
                        if ($j == count($currentPolygon)) {
                            $j = 0;
                        }
                    }
                    $return = $currentPolygon;
                }
            } else {
                $currentPolygon[] = $currentVertex;
                if (is_null($lastVertex)) {
                    // First point : we search every line from the point
                    foreach (array_keys($edges[$currentVertex->guid]) as $guid) {
                        $polygon = polygon_finder_recursive($graph, $currentPolygon, $vertices[$guid], $currentVertex);
                        if ($polygon !== false) {
                            $polygonList[] = $polygon;
                        }
                        $return = $polygonList;
                    }
                } else {
                    // Existing line : we follow the first available path with the smallest angle
                    $angleList = array();
                    foreach (array_keys($edges[$currentVertex->guid]) as $guid) {
                        // Stop condition : already passed through here in this direction
                        if ($lastVertex->guid != $guid && !isset($pathTable[$currentVertex->guid][$vertices[$guid]->guid])) {
                            $angleList[$guid] = Point::anglePolar($lastVertex, $currentVertex, $vertices[$guid]);
                        }
                    }
                    asort($angleList);
                    list($guid, $angle) = each($angleList);
                    if (!is_null($guid)) {
                        $return = polygon_finder_recursive($graph, $currentPolygon, $vertices[$guid], $currentVertex);
                    }
                }
            }
        }
        return $return;
    }