#Polyline

A polyline consists of an ordered list of locations, i.e. instances of the Coordinate class.

#Create a polyline

To create a polyline, just instantiate the class and add points:

<?php

use Location\Coordinate;
use Location\Polyline;

$polyline = new Polyline();
$polyline->addPoint(new Coordinate(52.5, 13.5));
$polyline->addPoint(new Coordinate(54.5, 12.5));
$polyline->addPoint(new Coordinate(55.5, 14.5));
?>

It’s possible to add points to the end of the polyline at every time with the addPoint() method.

Use addUniquePoint() to add unique points, i.e. points which doesn’t exist already in the polyline.

#Segments

It’s possible to get a list of polyline segments. Segments are returned as an array of Line instances.

<?php

use Location\Coordinate;
use Location\Polyline;

$track = new Polyline();
$track->addPoint(new Coordinate(52.5, 13.5));
$track->addPoint(new Coordinate(54.5, 12.5));
$track->addPoint(new Coordinate(55.5, 14.5));

foreach ($track->getSegments() as $segment) {
    printf(
        "Segment length: %0.2f kilometers\n",
        ($segment->getLength(new Haversine()) / 1000)
    );
}

The code above will produce the output below:

Segment length: 232.01 kilometers
Segment length: 169.21 kilometers

#Length

Length calculation is described in the Distance and Length section.

#Average Point

The getAveragePoint() method returns a point which latitude and longitude is the average of latitude/longitude values from all polyline points.

CAUTION: This method currently returns wrong values if the polyline crosses the date line at 180/-180 degrees longitude.

#Reverse Direction

It’s possible to get a new instance with reversed direction while the original polyline stays unchanged:

<?php

use Location\Coordinate;
use Location\Polyline;

$track = new Polyline();
$track->addPoint(new Coordinate(52.5, 13.5));
$track->addPoint(new Coordinate(54.5, 12.5));

$reversed = $track->getReverse();

print_r($reversed);

The code above will produce the output below:

Location\Polyline Object
(
    [points:protected] => Array
        (
            [0] => Location\Coordinate Object
                (
                    [lat:protected] => 54.5
                    [lng:protected] => 12.5
                    [ellipsoid:protected] => Location\Ellipsoid Object
                        (
                            [name:protected] => WGS-84
                            [a:protected] => 6378137
                            [f:protected] => 298.257223563
                        )

                )

            [1] => Location\Coordinate Object
                (
                    [lat:protected] => 52.5
                    [lng:protected] => 13.5
                    [ellipsoid:protected] => Location\Ellipsoid Object
                        (
                            [name:protected] => WGS-84
                            [a:protected] => 6378137
                            [f:protected] => 298.257223563
                        )

                )

        )

)