GooglePolyline

GooglePolyline is a Swift package that provides functionality for encoding and decoding polylines as per Google’s Encoded Polyline Algorithm. It offers the ability to simplify the polyline with a specified simplification factor, which can either be a direct value or automatically calculated based on a desired maximum length.

Features

• Encodes an array of CLLocation instances into a string that represents a Google Encoded Polyline.
• Decodes a string that represents a Google Encoded Polyline into an array of CLLocation instances.
• Decodes a string that represents a Google Encoded Polyline into a MKPolyline.
• Simplifies the polyline using the Douglas-Peucker algorithm.

Installation

Swift Package Manager

Add the following line to your dependencies in your Package.swift file:

.package(url: "https://github.com/podiumkit/GooglePolyline.git", from: "1.0.0"),

Then, include "GooglePolyline" as a dependency for your target:

.target(name: "YourTarget", dependencies: ["GooglePolyline"]),

Usage

Import the package in your Swift file:

import GooglePolyline

Create an instance of GooglePolyline:

let googlePolyline = GooglePolyline()

You can then encode and decode polylines as follows:

let locations: [CLLocation] = ...
let encodedPolyline = googlePolyline.encode(locations: locations)

let decodedLocations = googlePolyline.decode(polyline: encodedPolyline)
let decodedMKPolyline = googlePolyline.decodeToMKPolyline(polyline: encodedPolyline)

Implementation Details

The GooglePolyline class provides the primary functionality. You can control the simplification of the polyline by specifying a SimplificationFactor when initializing the class. This can be set to .automatic(maxLength: Int) to automatically calculate the simplification factor based on a maximum length, or .value(Double) to directly set the factor.

The encode(locations:) function takes an array of CLLocation instances and returns a string representing the Google Encoded Polyline. The decode(polyline:) function does the reverse, returning an array of CLLocation instances from an encoded polyline string. decodeToMKPolyline(polyline:) also decodes the polyline but returns a MKPolyline instance.

Legal

Google is a trademark of Google LLC. This software is neither endorsed nor otherwise related to Google LLC apart from being based on Google’s polyline encoding algorithm.