Some utility functions for osmdroid. Helps on using the library.

Utils.kt

import org.osmdroid.util.BoundingBox
import org.osmdroid.util.GeoPoint

/**
 * Computes the center point of all the ones in the list.
 * @author Arnau Mora
 * @since 20220302
 * @return The center point between all the ones in the list.
 */
fun List<GeoPoint>.computeCentroid(): GeoPoint {
    var latitude = 0.0
    var longitude = 0.0

    for (point in this) {
        latitude += point.latitude
        longitude += point.longitude
    }

    return GeoPoint(latitude / size, longitude / size)
}

/**
 * Gets the [BoundingBox] of a list of [GeoPoint]s. Will cause issues when called with less than
 * 2 elements on the list.
 * @author Arnau Mora
 * @since 20220401
 * @return A [BoundingBox] instance containing all the points of the list.
 * @throws IllegalStateException When the bounding box could not have been obtained.
 */
@Throws(IllegalStateException::class)
fun List<GeoPoint>.getBoundingBox(): BoundingBox {
    // Now get bounds
    var north: Double? = null
    var south: Double? = null
    var east: Double? = null
    var west: Double? = null

    for (position in this) {
        north = north?.let { Math.max(position.latitude, it) } ?: position.latitude
        south = south?.let { Math.min(position.latitude, it) } ?: position.latitude

        east = east?.let { Math.max(position.longitude, it) } ?: position.longitude
        west = west?.let { Math.min(position.longitude, it) } ?: position.longitude
    }

    if (north == null || south == null || east == null || west == null)
        throw IllegalStateException("Could not get directions. north=$north, south=$south, east=$east, west=$west")

    return BoundingBox(north, east, south, west)
}

/**
 * Computes the distance between two [GeoPoint]. Quite a dirty approach, using conversions to
 * [Location], but works as expected.
 * @author Arnau Mora
 * @since 20220401
 * @param other The point to compute the distance to.
 * @return The distance in meters between the two points.
 */
fun GeoPoint.distanceTo(other: GeoPoint): Float {
    val a = this.toLocation()
    val b = other.toLocation()
    return a.distanceTo(b)
}