mapguesser/src/Util/Geo/Bounds.php
Pőcze Bence 7159867db0 MAPG-111 query map area from DB
modify calculations to be in square km (instead of m)
2020-06-12 21:55:04 +02:00

109 lines
2.5 KiB
PHP

<?php namespace MapGuesser\Util\Geo;
class Bounds
{
const ONE_DEGREE_OF_LATITUDE_IN_KM = 111.132954;
private float $southLat = 90.0;
private float $westLng = 180.0;
private float $northLat = -90.0;
private float $eastLng = -180.0;
public function __construct(Position $position = null)
{
if ($position === null) {
return;
}
$lat = $position->getLat();
$lng = $position->getLng();
$this->northLat = $lat;
$this->westLng = $lng;
$this->southLat = $lat;
$this->eastLng = $lng;
}
public static function createDirectly(float $southLat, float $westLng, float $northLat, float $eastLng): Bounds
{
$instance = new static();
$instance->southLat = $southLat;
$instance->westLng = $westLng;
$instance->northLat = $northLat;
$instance->eastLng = $eastLng;
return $instance;
}
public function extend(Position $position): void
{
$lat = $position->getLat();
$lng = $position->getLng();
if ($lat < $this->southLat) {
$this->southLat = $lat;
}
if ($lng < $this->westLng) {
$this->westLng = $lng;
}
if ($lat > $this->northLat) {
$this->northLat = $lat;
}
if ($lng > $this->eastLng) {
$this->eastLng = $lng;
}
}
public function getSouthLat(): float
{
return $this->southLat;
}
public function getWestLng(): float
{
return $this->westLng;
}
public function getNorthLat(): float
{
return $this->northLat;
}
public function getEastLng(): float
{
return $this->eastLng;
}
public function calculateApproximateArea(): float
{
$dLat = $this->northLat - $this->southLat;
$dLng = $this->eastLng - $this->westLng;
$m = $dLat * static::ONE_DEGREE_OF_LATITUDE_IN_KM;
$a = $dLng * static::ONE_DEGREE_OF_LATITUDE_IN_KM * cos(deg2rad($this->northLat));
$c = $dLng * static::ONE_DEGREE_OF_LATITUDE_IN_KM * cos(deg2rad($this->southLat));
return $m * ($a + $c) / 2;
}
public function toArray(): array
{
return [
'south' => $this->southLat,
'west' => $this->westLng,
'north' => $this->northLat,
'east' => $this->eastLng,
];
}
public function toJson(): string
{
return json_encode($this->toArray());
}
}