How close is the geo-location to the path?

ClosestDistance.kt

// https://www.reddit.com/r/androiddev/comments/ert88w/asking_if_this_is_possible_to_do_with_maps_api/

fun closestDistance(point:LatLng, route:Polyline) : Double {

    var minDist = Double.MAX_VALUE
    for (i in 0 until (route.points?.size ?: 0) - 1) {
        val dist=lineDistance(point,route.points[i],route.points[i+1])
        if (dist<minDist){
            minDist=dist
        }
    }
    //minDist is in degrees, 111319.9 is meters per degree at the equator.
    return minDist * 111319.9
}

private fun lineDistance(point: LatLng, pathA: LatLng, pathB: LatLng) : Double {
    val x=point.latitude
    val y=point.longitude
    val x1=pathA.latitude
    val y1=pathA.longitude
    val x2=pathB.latitude
    val y2=pathB.longitude

    val A = x - x1
    val B = y - y1
    val C = x2 - x1
    val D = y2 - y1

    val dot = A * C + B * D
    val len_sq = C * C + D * D
    var param = -1.0
    if (len_sq != 0.0) //in case of 0 length line
        param = dot / len_sq
     val (xx,yy)=if (param < 0) {
        Pair(x1,y1)
    }
    else if (param > 1) {
        Pair(x2,y2)
    }
    else {
        Pair(x1 + param * C,y1 + param * D)
    }

    val dx = x - xx;
    val dy = y - yy;
     return Math.sqrt(dx * dx + dy * dy)
}