/**
* Return an array of all points within this QuadTree and its child nodes that fall
* within the specified bounding box
*
* @param QuadTreeBoundingBox $boundary The bounding box that we want to search
* @return QuadTreeXYPoint[]
**/
public function search(QuadTreeBoundingBox $boundary)
{
$results = array();
if ($this->boundingBox->encompasses($boundary) || $this->boundingBox->intersects($boundary)) {
// Test each point that falls within the current QuadTree node
foreach ($this->points as $point) {
// Test each point stored in this QuadTree node in turn, adding to the results array
// if it falls within the bounding box
if ($boundary->containsPoint($point)) {
$results[] = $point;
}
}
// If we have child QuadTree nodes....
if (isset($this->northWest)) {
// ... search each child node in turn, merging with any existing results
$results = array_merge($results, $this->northWest->search($boundary), $this->northEast->search($boundary), $this->southWest->search($boundary), $this->southEast->search($boundary));
}
}
return $results;
}
/**
* Identifies whether a specified bounding box completely encompasses this bounding box?
*
* @param QuadTreeBoundingBox $boundary The specified bounding box to test
* @return boolean Does the specified bounding box completely encompasses
* this bounding box?
*/
public function encompasses(QuadTreeBoundingBox $boundary)
{
return $boundary->startX() <= $this->startX() && $boundary->endX() >= $this->endX() && ($boundary->startY() <= $this->startY() && $boundary->endY() >= $this->endY());
}
