Location\Bearing\BearingEllipsoidal::directVincenty PHP Method

    private function directVincenty(Coordinate $point, $bearing, $distance)
    {
        $φ1 = deg2rad($point->getLat());
        $λ1 = deg2rad($point->getLng());
        $α1 = deg2rad($bearing);
        $a = $point->getEllipsoid()->getA();
        $b = $point->getEllipsoid()->getB();
        $f = 1 / $point->getEllipsoid()->getF();
        $sinα1 = sin($α1);
        $cosα1 = cos($α1);
        $tanU1 = (1 - $f) * tan($φ1);
        $cosU1 = 1 / sqrt(1 + $tanU1 * $tanU1);
        $sinU1 = $tanU1 * $cosU1;
        $σ1 = atan2($tanU1, $cosα1);
        $sinα = $cosU1 * $sinα1;
        $cosSqα = 1 - $sinα * $sinα;
        $uSq = $cosSqα * ($a * $a - $b * $b) / ($b * $b);
        $A = 1 + $uSq / 16384 * (4096 + $uSq * (-768 + $uSq * (320 - 175 * $uSq)));
        $B = $uSq / 1024 * (256 + $uSq * (-128 + $uSq * (74 - 47 * $uSq)));
        $σ = $distance / ($b * $A);
        $iterations = 0;
        do {
            $cos2σm = cos(2 * $σ1 + $σ);
            $sinσ = sin($σ);
            $cosσ = cos($σ);
            $Δσ = $B * $sinσ * ($cos2σm + $B / 4 * ($cosσ * (-1 + 2 * $cos2σm * $cos2σm) - $B / 6 * $cos2σm * (-3 + 4 * $sinσ * $sinσ) * (-3 + 4 * $cos2σm * $cos2σm)));
            $σs = $σ;
            $σ = $distance / ($b * $A) + $Δσ;
        } while (abs($σ - $σs) > 1.0E-12 && ++$iterations < 200);
        if ($iterations >= 200) {
            throw new NotConvergingException('Inverse Vincenty Formula did not converge');
        }
        $tmp = $sinU1 * $sinσ - $cosU1 * $cosσ * $cosα1;
        $φ2 = atan2($sinU1 * $cosσ + $cosU1 * $sinσ * $cosα1, (1 - $f) * sqrt($sinα * $sinα + $tmp * $tmp));
        $λ = atan2($sinσ * $sinα1, $cosU1 * $cosσ - $sinU1 * $sinσ * $cosα1);
        $C = $f / 16 * $cosSqα * (4 + $f * (4 - 3 * $cosSqα));
        $L = $λ - (1 - $C) * $f * $sinα * ($σ + $C * $sinσ * ($cos2σm + $C * $cosσ * (-1 + 2 * $cos2σm * $cos2σm)));
        $λ2 = fmod($λ1 + $L + 3 * M_PI, 2 * M_PI) - M_PI;
        $α2 = atan2($sinα, -$tmp);
        $α2 = fmod($α2 + 2 * M_PI, 2 * M_PI);
        return ['destination' => new Coordinate(rad2deg($φ2), rad2deg($λ2), $point->getEllipsoid()), 'bearing_final' => rad2deg($α2)];
    }