/**
* Tests the geohash halving function geohash::halve().
*
* @dataProvider geohashProvider
* @param string $geohash
*/
public function testHalve($geohash)
{
$north = geohash::neighbor($geohash, geohash::north);
$south = geohash::neighbor($geohash, geohash::south);
$east = geohash::neighbor($geohash, geohash::east);
$west = geohash::neighbor($geohash, geohash::west);
$outside_tests = array(geohash::decode($east), geohash::decode($west));
if ($north) {
$outside_tests[] = geohash::decode($north);
}
if ($south) {
$outside_tests[] = geohash::decode($south);
}
$north_half = geohash::halve($geohash, geohash::north);
$south_half = geohash::halve($geohash, geohash::south);
$east_half = geohash::halve($geohash, geohash::east);
$west_half = geohash::halve($geohash, geohash::west);
// do the obvious outside tests
foreach ($outside_tests as $test) {
$this->assertFalse($north_half->contains($test));
$this->assertFalse($south_half->contains($test));
$this->assertFalse($east_half->contains($test));
$this->assertFalse($west_half->contains($test));
}
// test points from the four quadrants
$box = geohash::decode_box($geohash);
$dlat = $box->north - $box->south;
$dlon = $box->east - $box->west;
$northwest = new geopoint($box->north - $dlat / 4, $box->west + $dlon / 4);
$northeast = new geopoint($box->north - $dlat / 4, $box->east - $dlon / 4);
$southwest = new geopoint($box->south + $dlat / 4, $box->west + $dlon / 4);
$southeast = new geopoint($box->south + $dlat / 4, $box->east - $dlon / 4);
$this->assertTrue($north_half->contains($northwest));
$this->assertTrue($north_half->contains($northeast));
$this->assertFalse($north_half->contains($southwest));
$this->assertFalse($north_half->contains($southeast));
$this->assertFalse($south_half->contains($northwest));
$this->assertFalse($south_half->contains($northeast));
$this->assertTrue($south_half->contains($southwest));
$this->assertTrue($south_half->contains($southeast));
$this->assertFalse($east_half->contains($northwest));
$this->assertTrue($east_half->contains($northeast));
$this->assertFalse($east_half->contains($southwest));
$this->assertTrue($east_half->contains($southeast));
$this->assertTrue($west_half->contains($northwest));
$this->assertFalse($west_half->contains($northeast));
$this->assertTrue($west_half->contains($southwest));
$this->assertFalse($west_half->contains($southeast));
// these points are from the four corners
$northwest = new geopoint($box->north, $box->west);
$northeast = new geopoint($box->north, $box->east);
$southwest = new geopoint($box->south, $box->west);
$southeast = new geopoint($box->south, $box->east);
$this->assertTrue($north_half->contains($northwest));
$this->assertTrue($north_half->contains($northeast));
$this->assertFalse($north_half->contains($southwest));
$this->assertFalse($north_half->contains($southeast));
$this->assertFalse($south_half->contains($northwest));
$this->assertFalse($south_half->contains($northeast));
$this->assertTrue($south_half->contains($southwest));
$this->assertTrue($south_half->contains($southeast));
$this->assertFalse($east_half->contains($northwest));
$this->assertTrue($east_half->contains($northeast));
$this->assertFalse($east_half->contains($southwest));
$this->assertTrue($east_half->contains($southeast));
$this->assertTrue($west_half->contains($northwest));
$this->assertFalse($west_half->contains($northeast));
$this->assertTrue($west_half->contains($southwest));
$this->assertFalse($west_half->contains($southeast));
// test the center
$center_point = new geopoint($box->north - $dlat / 2, $box->west + $dlon / 2);
$this->assertTrue($north_half->contains($center_point));
$this->assertTrue($south_half->contains($center_point));
$this->assertTrue($east_half->contains($center_point));
$this->assertTrue($west_half->contains($center_point));
}
/**
* Increase the size the of the circle.
* @param int $amount
* @return boolean success|failure
*/
public function expand($amount = 1)
{
if ($this->precision == 1) {
// currently unwilling to expand to cover the entire globe
return false;
}
$this->precision = max($this->precision - $amount, 1);
// shrink the geohash, grow the box
$center = substr($this->center_geohash, 0, $this->precision);
$box = geohash::decode_box($center);
$dlat = $box->north - $box->south;
$dlon = $box->east - $box->west;
$set = new geohash_set();
$set->add($center);
$quadrant = geohash::quadrant($this->center_geohash, $this->precision);
if ($quadrant == geohash::northeast || $quadrant == geohash::northwest) {
// north side
$north = geohash::neighbor($center, geohash::north);
if ($north) {
$set->add_set(geohash::halve($north, geohash::south));
if ($quadrant == geohash::northeast) {
$set->add_set(geohash::quarter(geohash::neighbor($north, geohash::east), geohash::southwest));
} else {
// northwest
$set->add_set(geohash::quarter(geohash::neighbor($north, geohash::west), geohash::southeast));
}
$box->north += $dlat / 2;
}
} else {
// south side
$south = geohash::neighbor($center, geohash::south);
if ($south) {
$set->add_set(geohash::halve($south, geohash::north));
if ($quadrant == geohash::southeast) {
$set->add_set(geohash::quarter(geohash::neighbor($south, geohash::east), geohash::northwest));
} else {
// southwest
$set->add_set(geohash::quarter(geohash::neighbor($south, geohash::west), geohash::northeast));
}
$box->south -= $dlat / 2;
}
}
if ($quadrant == geohash::northeast || $quadrant == geohash::southeast) {
// east side
$set->add_set(geohash::halve(geohash::neighbor($center, geohash::east), geohash::west));
$box->east += $dlon / 2;
} else {
// west side
$set->add_set(geohash::halve(geohash::neighbor($center, geohash::west), geohash::east));
$box->west -= $dlon / 2;
}
$this->geohash_set = $set;
$this->max_radius = min($this->center->distance_to_longitude($box->east), $this->center->distance_to_longitude($box->west));
if ($box->north < 90) {
$this->max_radius = min($this->center->distance_to_latitude(min($box->north, 90)), $this->max_radius);
}
if ($box->south > -90) {
$this->max_radius = min($this->center->distance_to_latitude(max($box->south, -90)), $this->max_radius);
}
return true;
}