/**
* Gets the surrounding nodes of the provided Node.
* @param Node $node
* @return array Surrounding nodeswhich are free in the grid and not on the closed list
*/
protected function getSurroundingNodes(Node $node)
{
$thresholdCost = 3 * $this->orthogonalCost;
$movementCost = $node->getMovementCost();
$estimatedMovementCost = $node->getEstimatedMovementCost();
if ($movementCost < $thresholdCost || $estimatedMovementCost < $thresholdCost) {
$threshold = 0;
} elseif ($movementCost < $thresholdCost * 5 || $estimatedMovementCost < $thresholdCost * 5) {
$threshold = 1;
} else {
$threshold = 2;
}
$x = $node->getPoint()->getX();
$y = $node->getPoint()->getY();
$minX = min(max($this->gridMinX, $x - 1), $this->gridMaxX);
$maxX = min(max($this->gridMinX, $x + 1), $this->gridMaxX);
$minY = min(max($this->gridMinY, $y - 1), $this->gridMaxY);
$maxY = min(max($this->gridMinY, $y + 1), $this->gridMaxY);
$surroundingNodes = array();
for ($i = $minX; $i <= $maxX; $i++) {
for ($j = $minY; $j <= $maxY; $j++) {
if ($i == $x && $j == $y) {
continue;
}
$point = new Point($i, $j);
$node = new Node($point);
$id = $node->getId();
if (array_key_exists($id, $this->closed)) {
continue;
}
if (!$this->grid->isFree($point, $threshold)) {
continue;
}
$surroundingNodes[$id] = $node;
}
}
return $surroundingNodes;
}
