Service class

gistfile1.txt

<?php

namespace App\Polylines;

class PathCleaner
{
    /**
     * Cleans up the polyline's path by trying to remove any incorrect path points.
     *
     * @param $path
     * @param int $maxDistance
     * @return array
     */
    public function clean($path, $maxDistance = 150)
    {
        $newPath = [];

        foreach ($path as $index => $point) {
            // First point in the original path always gets used.
            if ($index === 0) {
                $newPath[] = $point;
                continue;
            }

            // Calculate the distance between this point and the last.
            $previous = $path[$index - 1];
            $distance = $this->haversineGreatCircleDistance($previous[0], $previous[1], $point[0], $point[1]);

            // If the distance is above the threshold, we'll make this the end of the path. Otherwise keep going.
            if ($distance > $maxDistance) {
                break;
            }

            $newPath[] = $point;
        }

        return $newPath;
    }

    /**
     * Calculates the Haversine distance between to lat/lng pairs.
     *
     * @param $latitudeFrom
     * @param $longitudeFrom
     * @param $latitudeTo
     * @param $longitudeTo
     * @param int $earthRadius
     * @return int
     */
    protected function haversineGreatCircleDistance($latitudeFrom, $longitudeFrom, $latitudeTo, $longitudeTo, $earthRadius = 6371000) {
        $latFrom = deg2rad($latitudeFrom);
        $lonFrom = deg2rad($longitudeFrom);
        $latTo = deg2rad($latitudeTo);
        $lonTo = deg2rad($longitudeTo);

        $latDelta = $latTo - $latFrom;
        $lonDelta = $lonTo - $lonFrom;

        $angle = 2 * asin(sqrt(pow(sin($latDelta / 2), 2) +
                cos($latFrom) * cos($latTo) * pow(sin($lonDelta / 2), 2)));

        return $angle * $earthRadius;
    }
}