geofire-common/dist/geofire-common/index.d.ts

Location-based querying and filtering using Firebase

export declare const GEOHASH_PRECISION = 10;
export declare const BASE32 = "0123456789bcdefghjkmnpqrstuvwxyz";
export declare const EARTH_MERI_CIRCUMFERENCE = 40007860;
export declare const METERS_PER_DEGREE_LATITUDE = 110574;
export declare const BITS_PER_CHAR = 5;
export declare const MAXIMUM_BITS_PRECISION: number;
export declare const EARTH_EQ_RADIUS = 6378137;
export declare const E2 = 0.00669447819799;
export declare const EPSILON = 1e-12;
export declare type Geopoint = [number, number];
export declare type Geohash = string;
export declare type GeohashRange = [Geohash, Geohash];
/**
 * Validates the inputted key and throws an error if it is invalid.
 *
 * @param key The key to be verified.
 */
export declare function validateKey(key: string): void;
/**
 * Validates the inputted location and throws an error if it is invalid.
 *
 * @param location The [latitude, longitude] pair to be verified.
 */
export declare function validateLocation(location: Geopoint): void;
/**
 * Validates the inputted geohash and throws an error if it is invalid.
 *
 * @param geohash The geohash to be validated.
 */
export declare function validateGeohash(geohash: Geohash): void;
/**
 * Converts degrees to radians.
 *
 * @param degrees The number of degrees to be converted to radians.
 * @returns The number of radians equal to the inputted number of degrees.
 */
export declare function degreesToRadians(degrees: number): number;
/**
 * Generates a geohash of the specified precision/string length from the  [latitude, longitude]
 * pair, specified as an array.
 *
 * @param location The [latitude, longitude] pair to encode into a geohash.
 * @param precision The length of the geohash to create. If no precision is specified, the
 * global default is used.
 * @returns The geohash of the inputted location.
 */
export declare function geohashForLocation(location: Geopoint, precision?: number): Geohash;
/**
 * Calculates the number of degrees a given distance is at a given latitude.
 *
 * @param distance The distance to convert.
 * @param latitude The latitude at which to calculate.
 * @returns The number of degrees the distance corresponds to.
 */
export declare function metersToLongitudeDegrees(distance: number, latitude: number): number;
/**
 * Calculates the bits necessary to reach a given resolution, in meters, for the longitude at a
 * given latitude.
 *
 * @param resolution The desired resolution.
 * @param latitude The latitude used in the conversion.
 * @return The bits necessary to reach a given resolution, in meters.
 */
export declare function longitudeBitsForResolution(resolution: number, latitude: number): number;
/**
 * Calculates the bits necessary to reach a given resolution, in meters, for the latitude.
 *
 * @param resolution The bits necessary to reach a given resolution, in meters.
 * @returns Bits necessary to reach a given resolution, in meters, for the latitude.
 */
export declare function latitudeBitsForResolution(resolution: number): number;
/**
 * Wraps the longitude to [-180,180].
 *
 * @param longitude The longitude to wrap.
 * @returns longitude The resulting longitude.
 */
export declare function wrapLongitude(longitude: number): number;
/**
 * Calculates the maximum number of bits of a geohash to get a bounding box that is larger than a
 * given size at the given coordinate.
 *
 * @param coordinate The coordinate as a [latitude, longitude] pair.
 * @param size The size of the bounding box.
 * @returns The number of bits necessary for the geohash.
 */
export declare function boundingBoxBits(coordinate: Geopoint, size: number): number;
/**
 * Calculates eight points on the bounding box and the center of a given circle. At least one
 * geohash of these nine coordinates, truncated to a precision of at most radius, are guaranteed
 * to be prefixes of any geohash that lies within the circle.
 *
 * @param center The center given as [latitude, longitude].
 * @param radius The radius of the circle in meters.
 * @returns The center of the box, and the eight bounding box points.
 */
export declare function boundingBoxCoordinates(center: Geopoint, radius: number): [Geopoint, Geopoint, Geopoint, Geopoint, Geopoint, Geopoint, Geopoint, Geopoint, Geopoint];
/**
 * Calculates the bounding box query for a geohash with x bits precision.
 *
 * @param geohash The geohash whose bounding box query to generate.
 * @param bits The number of bits of precision.
 * @returns A [start, end] pair of geohashes.
 */
export declare function geohashQuery(geohash: Geohash, bits: number): GeohashRange;
/**
 * Calculates a set of query bounds to fully contain a given circle, each being a [start, end] pair
 * where any geohash is guaranteed to be lexicographically larger than start and smaller than end.
 *
 * @param center The center given as [latitude, longitude] pair.
 * @param radius The radius of the circle.
 * @return An array of geohash query bounds, each containing a [start, end] pair.
 */
export declare function geohashQueryBounds(center: Geopoint, radius: number): GeohashRange[];
/**
 * Method which calculates the distance, in kilometers, between two locations,
 * via the Haversine formula. Note that this is approximate due to the fact that the
 * Earth's radius varies between 6356.752 km and 6378.137 km.
 *
 * @param location1 The [latitude, longitude] pair of the first location.
 * @param location2 The [latitude, longitude] pair of the second location.
 * @returns The distance, in kilometers, between the inputted locations.
 */
export declare function distanceBetween(location1: Geopoint, location2: Geopoint): number;