## Geometry Library Google Maps API V3
PHP Geometry Library provides utility functions for the computation of geometric data on the surface of the Earth. Code ported from Google [Maps Android API](https://github.com/googlemaps/android-maps-utils/).
Features
------------
* [Spherical](https://developers.google.com/maps/documentation/javascript/reference#spherical) contains spherical geometry utilities allowing you to compute angles, distances and areas from latitudes and longitudes.
* [Poly](https://developers.google.com/maps/documentation/javascript/reference#poly) utility functions for computations involving polygons and polylines.
* [Encoding](https://developers.google.com/maps/documentation/javascript/reference#encoding) utilities for polyline encoding and decoding.
Dependency
------------
* [PHP 5](http://php.net/)
Installation
------------
Issue following command:
```php
composer require alexpechkarev/geometry-library:1.0.4
```
Alternatively edit composer.json by adding following line and run **`composer update`**
```php
"require": {
....,
"alexpechkarev/geometry-library":"1.0.4",
},
```
Usage
------------
Here is an example of using GeometryLibrary:
```php
$response = \GeometryLibrary\SphericalUtil::computeHeading(
['lat' => 25.775, 'lng' => -80.190], // from array [lat, lng]
['lat' => 21.774, 'lng' => -80.190]); // to array [lat, lng]
echo $response; // -180
$response = \GeometryLibrary\SphericalUtil::computeDistanceBetween(
['lat' => 25.775, 'lng' => -80.190], //from array [lat, lng]
['lat' => 21.774, 'lng' => -80.190]); // to array [lat, lng]
echo $response; // 444891.52998049
$response = \GeometryLibrary\PolyUtil::isLocationOnEdge(
['lat' => 25.774, 'lng' => -80.190], // point array [lat, lng]
[ // poligon arrays of [lat, lng]
['lat' => 25.774, 'lng' => -80.190],
['lat' => 18.466, 'lng' => -66.118],
['lat' => 32.321, 'lng' => -64.757]
]) ;
echo $response; // true
$response = \GeometryLibrary\PolyUtil::isLocationOnPath(
['lat' => 25.771, 'lng' => -80.190], // point array [lat, lng]
[ // poligon arrays of [lat, lng]
['lat' => 25.774, 'lng' => -80.190],
['lat' => 18.466, 'lng' => -66.118],
['lat' => 32.321, 'lng' => -64.757]
]);
echo $response; // false
$response = \GeometryLibrary\PolyUtil::containsLocation(
['lat' => 23.886, 'lng' => -65.269], // point array [lat, lng]
[ // poligon arrays of [lat, lng]
['lat' => 25.774, 'lng' => -80.190],
['lat' => 18.466, 'lng' => -66.118],
['lat' => 32.321, 'lng' => -64.757]
]);
echo $response; // false
$response = \GeometryLibrary\PolyUtil::distanceToLine(
['lat' => 61.387002, 'lng' => 23.890636], // point array [lat, lng]
['lat' => 61.487002, 'lng' => 23.790636], // line startpoint array [lat, lng]
['lat' => 60.48047, 'lng' => 22.052754] // line endpoint array [lat, lng]
);
echo $response; // 12325.124046196 in meters
$response = \GeometryLibrary\PolyUtil::encode(
[
['lat' => 38.5, 'lng' => -120.2],
['lat' => 40.7, 'lng' => -120.95],
['lat' => 43.252, 'lng' => -126.453]
]);
echo $response; // '_p~iF~ps|U_ulLnnqC_mqNvxq`@'
$response = \GeometryLibrary\PolyUtil::decode('_p~iF~ps|U_ulLnnqC_mqNvxq`@');
echo $response; /** array (size=3)
0 =>
array (size=2)
'lat' => float 38.5
'lng' => float -120.2
1 =>
array (size=2)
'lat' => float 40.7
'lng' => float -120.95
2 =>
array (size=2)
'lat' => float 43.252
'lng' => float -126.453
*/
```
Available methods
------------
## PolyUtil class
* [`containsLocation($point, $polygon, $geodesic = false)`](#containsLocation)
* [`isLocationOnEdge($point, $polygon, $tolerance = self::DEFAULT_TOLERANCE, $geodesic = true)`](#isLocationOnEdge)
* [`isLocationOnPath($point, $polyline, $tolerance = self::DEFAULT_TOLERANCE, $geodesic = true)`](#isLocationOnPath)
* [`distanceToLine($p, $start, $end)`](#distanceToLine)
* [`decode($encodedPath)`](#decode)
* [`encode($path)`](#encode)
## SphericalUtil class
* [`computeHeading($from, $to)`](#computeHeading)
* [`computeOffset($from, $distance, $heading)`](#computeOffset)
* [`computeOffsetOrigin($to, $distance, $heading)`](#computeOffsetOrigin)
* [`interpolate($from, $to, $fraction)`](#interpolate)
* [`computeDistanceBetween( $from, $to)`](#computeDistanceBetween)
* [`computeLength($path)`](#computeLength)
* [`computeArea($path)`](#computeArea)
* [`computeSignedArea($path)`](#computeSignedArea)
---
**`containsLocation( $point, $polygon, $geodesic = false )`** - To find whether a given point falls within a polygon
* `$point` - ['lat' => 38.5, 'lng' => -120.2 ]
* `$polygon` - [ ['lat' => 38.5, 'lng' => -120.2], ['lat' => 40.7, 'lng' => -120.95], ['lat' => 43.252, 'lng' => -126.453]]
* `$geodesic` - boolean
Returns boolean
```php
$response = \GeometryLibrary\PolyUtil::containsLocation(
['lat' => 23.886, 'lng' => -65.269], // point array [lat, lng]
[ // poligon arrays of [lat, lng]
['lat' => 25.774, 'lng' => -80.190],
['lat' => 18.466, 'lng' => -66.118],
['lat' => 32.321, 'lng' => -64.757]
]);
echo $response; // false
```
---
**`isLocationOnEdge( $point, $polygon, $tolerance = self::DEFAULT_TOLERANCE, $geodesic = true )`** - To determine whether a point falls on or near a polyline, or on or near the edge of a polygon, within a specified tolerance in meters.
* `$point` - ['lat' => 25.774, 'lng' => -80.190 ]
* `$polygon` - [ ['lat' => 38.5, 'lng' => -120.2], ['lat' => 40.7, 'lng' => -120.95], ['lat' => 43.252, 'lng' => -126.453]]
* `$tolerance` - tolerance value in degrees
* `$geodesic` - boolean
Returns boolean
```php
$response = \GeometryLibrary\PolyUtil::isLocationOnEdge(
['lat' => 25.774, 'lng' => -80.190], // point array [lat, lng]
[ // poligon arrays of [lat, lng]
['lat' => 25.774, 'lng' => -80.190],
['lat' => 18.466, 'lng' => -66.118],
['lat' => 32.321, 'lng' => -64.757]
]) ;
echo $response; // true
```
---
**`isLocationOnPath( $point, $polygon, $tolerance = self::DEFAULT_TOLERANCE, $geodesic = true )`** - To determine whether a point falls on or near a polyline, within a specified tolerance in meters
* `$point` - ['lat' => 25.774, 'lng' => -80.190 ]
* `$polygon` - [ ['lat' => 38.5, 'lng' => -120.2], ['lat' => 40.7, 'lng' => -120.95], ['lat' => 43.252, 'lng' => -126.453]]
* `$tolerance` - tolerance value in degrees
* `$geodesic` - boolean
Returns boolean
```php
$response = \GeometryLibrary\PolyUtil::isLocationOnPath(
['lat' => 25.774, 'lng' => -80.190], // point array [lat, lng]
[ // poligon arrays of [lat, lng]
['lat' => 25.774, 'lng' => -80.190],
['lat' => 18.466, 'lng' => -66.118],
['lat' => 32.321, 'lng' => -64.757]
]) ;
echo $response; // true
```
---
**`distanceToLine( $p, $start, $end )`** - To calculate distance from a point to line start->end on sphere.
* `$p` - ['lat' => 61.387002, 'lng' => 23.890636]
* `$start` - ['lat' => 61.487002, 'lng' => 23.790636]
* `$end` - ['lat' => 60.48047, 'lng' => 22.052754]
Returns distance from a point to line
```php
$response = \GeometryLibrary\PolyUtil::distanceToLine(
['lat' => 61.387002, 'lng' => 23.890636], // point array [lat, lng]
['lat' => 61.487002, 'lng' => 23.790636], // line startpoint array [lat, lng]
['lat' => 60.48047, 'lng' => 22.052754] // line endpoint array [lat, lng]
);
echo $response; // 12325.124046196 in meters
```
---
**`decode( $encodedPath )`** - Decodes an encoded path string into a sequence of LatLngs.
* `$encodedPath` - string '_p~iF~ps|U_ulLnnqC_mqNvxq`@'
Returns array
```php
$response = \GeometryLibrary\PolyUtil::decode('_p~iF~ps|U_ulLnnqC_mqNvxq`@');
echo $response; /** array (size=3)
0 =>
array (size=2)
'lat' => float 38.5
'lng' => float -120.2
1 =>
array (size=2)
'lat' => float 40.7
'lng' => float -120.95
2 =>
array (size=2)
'lat' => float 43.252
'lng' => float -126.453
*/
```
---
**`encode( $path )`** - Encodes a sequence of LatLngs into an encoded path string.
* `$path` - [ ['lat' => 38.5, 'lng' => -120.2], ['lat' => 40.7, 'lng' => -120.95], ['lat' => 43.252, 'lng' => -126.453] ]
Returns string
```php
$response = \GeometryLibrary\PolyUtil::encode(
[
['lat' => 38.5, 'lng' => -120.2],
['lat' => 40.7, 'lng' => -120.95],
['lat' => 43.252, 'lng' => -126.453]
]);
echo $response; // '_p~iF~ps|U_ulLnnqC_mqNvxq`@'
```
---
**`computeHeading( $from, $to )`** - Returns the heading from one LatLng to another LatLng.
* `$from` - ['lat' => 38.5, 'lng' => -120.2]
* `$to` - ['lat' => 40.7, 'lng' => -120.95]
Returns int
```php
$response = \GeometryLibrary\SphericalUtil::computeHeading(
['lat' => 25.775, 'lng' => -80.190],
['lat' => 21.774, 'lng' => -80.190]));
echo $response; // -180
```
---
**`computeOffset( $from, $distance, $heading )`** - Returns the LatLng resulting from moving a distance from an origin in the specified heading.
* `$from` - ['lat' => 38.5, 'lng' => -120.2]
* `$distance` - number, the distance to travel
* `$heading` - number, the heading in degrees clockwise from north
Returns array
```php
$response = \GeometryLibrary\SphericalUtil::computeOffset(['lat' => 25.775, 'lng' => -80.190], 152, 120);
echo $response; /** array (size=2)
'lat' => float 25.774316510639
'lng' => float -80.188685385944
*/
```
---
**`computeOffsetOrigin( $from, $distance, $heading )`** - Returns the location of origin when provided with a LatLng destination, meters travelled and original heading. Headings are expressed in degrees clockwise from North.
* `$from` - ['lat' => 38.5, 'lng' => -120.2]
* `$distance` - number, the distance to travel
* `$heading` - number, the heading in degrees clockwise from north
Returns array
```php
$response = \GeometryLibrary\SphericalUtil::computeOffsetOrigin(['lat' => 25.775, 'lng' => -80.190], 152, 120);
echo $response; /** array (size=2)
'lat' => float 14.33435503928
'lng' => float -263248.24242931
*/
```
---
**`interpolate( $from, $to, $fraction )`** - Returns the LatLng which lies the given fraction of the way between the origin LatLng and the destination LatLng.
* `$from` - ['lat' => 38.5, 'lng' => -120.2]
* `$to` - ['lat' => 38.5, 'lng' => -120.2]
* `$fraction` - number, a fraction of the distance to travel
Returns array
```php
$response = \GeometryLibrary\SphericalUtil::interpolate(['lat' => 25.775, 'lng' => -80.190],
['lat' => 26.215, 'lng' => -81.218], 2);
echo $response; /** array (size=2)
'lat' => float 26.647635362403
'lng' => float -82.253737943391
*/
```
---
**`computeDistanceBetween( $from, $to )`** - Returns the distance, in meters, between two LatLngs. You can optionally specify a custom radius. The radius defaults to the radius of the Earth.
* `$from` - ['lat' => 38.5, 'lng' => -120.2]
* `$to` - ['lat' => 38.5, 'lng' => -120.2]
Returns float
```php
$response = \GeometryLibrary\SphericalUtil::computeDistanceBetween(['lat' => 25.775, 'lng' => -80.190], ['lat' => 26.215, 'lng' => -81.218]);
echo $response; //float 113797.92421349
```
---
**`computeLength( $path )`** - Returns the length of the given path, in meters, on Earth.
* `$path` - [ ['lat' => 38.5, 'lng' => -120.2], ['lat' => 40.7, 'lng' => -120.95], ['lat' => 43.252, 'lng' => -126.453] ]
Returns float
```php
$response = \GeometryLibrary\SphericalUtil::computeLength([
['lat' => 38.5, 'lng' => -120.2],
['lat' => 40.7, 'lng' => -120.95],
['lat' => 43.252, 'lng' => -126.453]
]);
echo $response; //float 788906.98459431
```
---
**`computeArea( $path )`** - Returns the area of a closed path.
* `$path` - [ ['lat' => 38.5, 'lng' => -120.2], ['lat' => 40.7, 'lng' => -120.95], ['lat' => 43.252, 'lng' => -126.453] ]
Returns float
```php
$response = \GeometryLibrary\SphericalUtil::computeArea([
['lat' => 38.5, 'lng' => -120.2],
['lat' => 40.7, 'lng' => -120.95],
['lat' => 43.252, 'lng' => -126.453]
]);
echo $response; //float 44766785529.143
```
---
**`computeSignedArea( $path )`** - Returns the signed area of a closed path.
* `$path` - [ ['lat' => 38.5, 'lng' => -120.2], ['lat' => 40.7, 'lng' => -120.95], ['lat' => 43.252, 'lng' => -126.453] ]
Returns float
```php
$response = \GeometryLibrary\SphericalUtil::computeSignedArea([
['lat' => 38.5, 'lng' => -120.2],
['lat' => 40.7, 'lng' => -120.95],
['lat' => 43.252, 'lng' => -126.453]
]);
echo $response; //float 44766785529.143
```
---
Support
-------
[Please open an issue on GitHub](https://github.com/alexpechkarev/geometry-library/issues)
License
-------
Geometry Library Google Maps API V3 is released under the MIT License. See the bundled
[LICENSE](https://github.com/alexpechkarev/geometry-library/blob/master/LICENSE)
file for details.