Distance Between a Point and a Line

It's possible to calculate the shortest distance between a point and a Line. As Polyline and Polygon are also built upon the Line class it's also possible to calculate distances from a point the polyline/polygon by iterating over their segments.

The following image explains how the distance is calcualated: P and R are located in such a way that the nearest distance to the line is the distance between P, R and the line end points. Point Q is nearer to the actual line than to any of the end points, so the actual distance is the perpendicular distance between Q and the line.

Point to Line Distance

Example

<?php

use Location\Coordinate;
use Location\Distance\Vincenty;
use Location\Line;
use Location\Utility\PointToLineDistance;

$point = new Coordinate(52.5, 13.5);
$line = new Line(
    new Coordinate(52.5, 13.1),
    new Coordinate(52.5, 13.1)
);

$pointToLineDistanceCalculator = new PointToLineDistance(new Vincenty());

printf(
    'Distance from point to line: %.1f meters%s',
    $pointToLineDistanceCalculator->getDistance($point, $line),
    PHP_EOL
);

The code above will produce the output below:

Distance from point to line: 27164.1 meters