public function centroid()
{
if ($this->isEmpty()) {
return NULL;
}
if ($this->geos()) {
return GeoPHP::geosToGeometry($this->geos()->centroid());
}
$exterior_ring = $this->components[0];
$pts = $exterior_ring->getComponents();
$c = count($pts);
if ((int) $c == '0') {
return NULL;
}
$cn = array('x' => '0', 'y' => '0');
$a = $this->area(TRUE, TRUE);
// If this is a polygon with no area. Just return the first point.
if ($a == 0) {
return $this->exteriorRing()->pointN(1);
}
foreach ($pts as $k => $p) {
$j = ($k + 1) % $c;
$P = $p->getX() * $pts[$j]->getY() - $p->getY() * $pts[$j]->getX();
$cn['x'] = $cn['x'] + ($p->getX() + $pts[$j]->getX()) * $P;
$cn['y'] = $cn['y'] + ($p->getY() + $pts[$j]->getY()) * $P;
}
$cn['x'] = $cn['x'] / (6 * $a);
$cn['y'] = $cn['y'] / (6 * $a);
$centroid = new Point($cn['x'], $cn['y']);
return $centroid;
}
/**
* Read WKT string into geometry objects
*
* @param string $WKT A WKT string
*
* @return Geometry
*/
public function read($wkt)
{
$wkt = trim($wkt);
// If it contains a ';', then it contains additional SRID data
if (strpos($wkt, ';')) {
$parts = explode(';', $wkt);
$wkt = $parts[1];
$eparts = explode('=', $parts[0]);
$srid = $eparts[1];
} else {
$srid = NULL;
}
// If geos is installed, then we take a shortcut and let it parse the WKT
if (GeoPHP::geosInstalled()) {
$reader = new GEOSWKTReader();
if ($srid) {
$geom = GeoPHP::geosToGeometry($reader->read($wkt));
$geom->setSRID($srid);
return $geom;
} else {
return GeoPHP::geosToGeometry($reader->read($wkt));
}
}
$wkt = str_replace(', ', ',', $wkt);
// For each geometry type, check to see if we have a match at the
// beginning of the string. If we do, then parse using that type
foreach (GeoPHP::geometryList() as $geom_type) {
$wkt_geom = strtoupper($geom_type);
if (strtoupper(substr($wkt, 0, strlen($wkt_geom))) == $wkt_geom) {
$data_string = $this->getDataString($wkt);
$method = 'parse' . $geom_type;
if ($srid) {
$geom = $this->{$method}($data_string);
$geom->setSRID($srid);
return $geom;
} else {
return $this->{$method}($data_string);
}
}
}
}
public function getBBox()
{
if ($this->isEmpty()) {
return NULL;
}
if ($this->geos()) {
$envelope = $this->geos()->envelope();
if ($envelope->typeName() == 'Point') {
return GeoPHP::geosToGeometry($envelope)->getBBOX();
}
$geos_ring = $envelope->exteriorRing();
return array('maxy' => $geos_ring->pointN(3)->getY(), 'miny' => $geos_ring->pointN(1)->getY(), 'maxx' => $geos_ring->pointN(1)->getX(), 'minx' => $geos_ring->pointN(3)->getX());
}
// Go through each component and get the max and min x and y
$i = 0;
foreach ($this->components as $component) {
$component_bbox = $component->getBBox();
// On the first run through, set the bbox to the component bbox
if ($i == 0) {
$maxx = $component_bbox['maxx'];
$maxy = $component_bbox['maxy'];
$minx = $component_bbox['minx'];
$miny = $component_bbox['miny'];
}
// Do a check and replace on each boundary, slowly growing the bbox
$maxx = $component_bbox['maxx'] > $maxx ? $component_bbox['maxx'] : $maxx;
$maxy = $component_bbox['maxy'] > $maxy ? $component_bbox['maxy'] : $maxy;
$minx = $component_bbox['minx'] < $minx ? $component_bbox['minx'] : $minx;
$miny = $component_bbox['miny'] < $miny ? $component_bbox['miny'] : $miny;
$i++;
}
return array('maxy' => $maxy, 'miny' => $miny, 'maxx' => $maxx, 'minx' => $minx);
}
public function simplify($tolerance, $preserveTopology = FALSE)
{
if ($this->geos()) {
return GeoPHP::geosToGeometry($this->geos()->simplify($tolerance, $preserveTopology));
}
}
