radar-wp/vendor/phayes/geophp/lib/geometry/Collection.class.php
2015-02-24 16:25:12 +01:00

294 lines
8 KiB
PHP

<?php
/**
* Collection: Abstract class for compound geometries
*
* A geometry is a collection if it is made up of other
* component geometries. Therefore everything but a Point
* is a Collection. For example a LingString is a collection
* of Points. A Polygon is a collection of LineStrings etc.
*/
abstract class Collection extends Geometry
{
public $components = array();
/**
* Constructor: Checks and sets component geometries
*
* @param array $components array of geometries
*/
public function __construct($components = array()) {
if (!is_array($components)) {
throw new Exception("Component geometries must be passed as an array");
}
foreach ($components as $component) {
if ($component instanceof Geometry) {
$this->components[] = $component;
}
else {
throw new Exception("Cannot create a collection with non-geometries");
}
}
}
/**
* Returns Collection component geometries
*
* @return array
*/
public function getComponents() {
return $this->components;
}
public function centroid() {
if ($this->isEmpty()) return NULL;
if ($this->geos()) {
$geos_centroid = $this->geos()->centroid();
if ($geos_centroid->typeName() == 'Point') {
return geoPHP::geosToGeometry($this->geos()->centroid());
}
}
// As a rough estimate, we say that the centroid of a colletion is the centroid of it's envelope
// @@TODO: Make this the centroid of the convexHull
// Note: Outside of polygons, geometryCollections and the trivial case of points, there is no standard on what a "centroid" is
$centroid = $this->envelope()->centroid();
return $centroid;
}
public function getBBox() {
if ($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 asArray() {
$array = array();
foreach ($this->components as $component) {
$array[] = $component->asArray();
}
return $array;
}
public function area() {
if ($this->geos()) {
return $this->geos()->area();
}
$area = 0;
foreach ($this->components as $component) {
$area += $component->area();
}
return $area;
}
// By default, the boundary of a collection is the boundary of it's components
public function boundary() {
if ($this->isEmpty()) return new LineString();
if ($this->geos()) {
return $this->geos()->boundary();
}
$components_boundaries = array();
foreach ($this->components as $component) {
$components_boundaries[] = $component->boundary();
}
return geoPHP::geometryReduce($components_boundaries);
}
public function numGeometries() {
return count($this->components);
}
// Note that the standard is 1 based indexing
public function geometryN($n) {
$n = intval($n);
if (array_key_exists($n-1, $this->components)) {
return $this->components[$n-1];
}
else {
return NULL;
}
}
public function length() {
$length = 0;
foreach ($this->components as $delta => $component) {
$length += $component->length();
}
return $length;
}
public function greatCircleLength($radius = 6378137) {
$length = 0;
foreach ($this->components as $component) {
$length += $component->greatCircleLength($radius);
}
return $length;
}
public function haversineLength() {
$length = 0;
foreach ($this->components as $component) {
$length += $component->haversineLength();
}
return $length;
}
public function dimension() {
$dimension = 0;
foreach ($this->components as $component) {
if ($component->dimension() > $dimension) {
$dimension = $component->dimension();
}
}
return $dimension;
}
// A collection is empty if it has no components OR all it's components are empty
public function isEmpty() {
if (!count($this->components)) {
return TRUE;
}
else {
foreach ($this->components as $component) {
if (!$component->isEmpty()) return FALSE;
}
return TRUE;
}
}
public function numPoints() {
$num = 0;
foreach ($this->components as $component) {
$num += $component->numPoints();
}
return $num;
}
public function getPoints() {
$points = array();
foreach ($this->components as $component) {
$points = array_merge($points, $component->getPoints());
}
return $points;
}
public function equals($geometry) {
if ($this->geos()) {
return $this->geos()->equals($geometry->geos());
}
// To test for equality we check to make sure that there is a matching point
// in the other geometry for every point in this geometry.
// This is slightly more strict than the standard, which
// uses Within(A,B) = true and Within(B,A) = true
// @@TODO: Eventually we could fix this by using some sort of simplification
// method that strips redundant vertices (that are all in a row)
$this_points = $this->getPoints();
$other_points = $geometry->getPoints();
// First do a check to make sure they have the same number of vertices
if (count($this_points) != count($other_points)) {
return FALSE;
}
foreach ($this_points as $point) {
$found_match = FALSE;
foreach ($other_points as $key => $test_point) {
if ($point->equals($test_point)) {
$found_match = TRUE;
unset($other_points[$key]);
break;
}
}
if (!$found_match) {
return FALSE;
}
}
// All points match, return TRUE
return TRUE;
}
public function isSimple() {
if ($this->geos()) {
return $this->geos()->isSimple();
}
// A collection is simple if all it's components are simple
foreach ($this->components as $component) {
if (!$component->isSimple()) return FALSE;
}
return TRUE;
}
public function explode() {
$parts = array();
foreach ($this->components as $component) {
$parts = array_merge($parts, $component->explode());
}
return $parts;
}
// Not valid for this geometry type
// --------------------------------
public function x() { return NULL; }
public function y() { return NULL; }
public function startPoint() { return NULL; }
public function endPoint() { return NULL; }
public function isRing() { return NULL; }
public function isClosed() { return NULL; }
public function pointN($n) { return NULL; }
public function exteriorRing() { return NULL; }
public function numInteriorRings() { return NULL; }
public function interiorRingN($n) { return NULL; }
public function pointOnSurface() { return NULL; }
}