.NET Polyline Algorithm (.NET Standard 2.1)

Lightweight high=performance .NET Standard 2.1 library implementing Google Polyline Algorithm.

Prerequisites

.NET Polyline Algorithm is avalable as a NuGet package PolylineAlgorithm targeting .NET Standard 2.1.

Command line:

Install-Package PolylineAlgorithm

NuGet Package Manager:

PolylineAlgorithm

Hot to use it

There are three ways how to use .NET Polyline Algorithm library based on your needs. For each is available Encode and Decode methods.

Static methods

Whenever you just need to encode or decode Google polyline you can use static methods defined in static PolylineAlgorithm class.

Decoding

	string polyline = "polyline";
	IEnumerable<(double, double)> coordinates = PolylineAlgorithm.Decode(polyline);

Encoding

	IEnumerable<(double, double)> coordinates = new (double, double) [] { (35.635, 76.27182), (35.2435, 75.625), ... };
	string polyline = PolylineAlgorithm.Encode(coordinates);

Default instance

If you need to use dependency injection, you would like to have instance to deliver the work for you. In that case you can use default instance of PolylineEncoding class, which implements IPolylineEncoding<(double Latitude, double Longitude)> interface.

Decoding

	string polyline = "polyline";
	var encoding = new PolylineEncoding();
	IEnumerable<(double, double)> coordinates = encoding.Decode(polyline);

Encoding

	IEnumerable<(double, double)> coordinates = new (double, double) [] { (35.635, 76.27182), (35.2435, 75.625), ... };
	var encoding = new PolylineEncoding();
	string polyline = encoding.Encode(coordinates);

Inherited base class

There may be a scenario you need to pass and return different types to and from without a need to add another extra layer. In this case you can inherit PolylineEncodingBase class and override template methods CreateResult and GetCoordinates.

Inheriting

	public class MyPolylineEncoding : PolylineEncodingBase<Coordinate> {
	
		protected override Coordinate CreateResult(double latitude, double longitude) {
				return new Coordinate(latitude, longitude);
		}
	
		protected override (double Latitude, double Longitude) GetCoordinate(Coordinate source) {
				return (source.Latitude, source.Longitude);
		}
		
	}

Decoding

	string polyline = "polyline";
	var encoding = new MyPolylineEncoding();
	IEnumerable<Coordinate> coordinates = encoding.Decode(polyline);

Encoding

	IEnumerable<Coordinate> coordinates = new Coordinate [] { new Coordinate(35.635, 76.27182), new Coordinate(35.2435, 75.625), ... };
	var encoding = new MyPolylineEncoding();
	string polyline = encoding.Encode(coordinates);

Performance

Decode

BenchmarkDotNet v0.14.0, Windows 11 (10.0.26100.2894)
Apple Silicon, 4 CPU, 4 logical and 4 physical cores
.NET SDK 9.0.102
  [Host]     : .NET 9.0.1 (9.0.124.61010), Arm64 RyuJIT AdvSIMD
  Job-CJKHIS : .NET 5.0.17 (5.0.1722.21314), Arm64 RyuJIT AdvSIMD
  Job-GAHPKM : .NET 6.0.36 (6.0.3624.51421), Arm64 RyuJIT AdvSIMD
  Job-KWIIGA : .NET 7.0.20 (7.0.2024.26716), Arm64 RyuJIT AdvSIMD
  Job-ZMWUEM : .NET 8.0.12 (8.0.1224.60305), Arm64 RyuJIT AdvSIMD
  Job-EQIHVN : .NET 9.0.1 (9.0.124.61010), Arm64 RyuJIT AdvSIMD

Method	Runtime	Mean	Error	StdDev	Ratio	RatioSD	Rank	Gen0	Gen1	Allocated	Alloc Ratio
Cloudikka_PolylineEncoding_Decode	.NET 5.0	1,768.2 ns	7.36 ns	6.88 ns	1.29	0.01	3	0.4959	0.0019	3120 B	3.82
PolylineDecoder_Decode	.NET 5.0	1,367.1 ns	7.91 ns	6.61 ns	1.00	0.01	2	0.1297	-	816 B	1.00
Polyliner_Decode	.NET 5.0	1,218.0 ns	3.79 ns	3.17 ns	0.89	0.00	1	0.5169	0.0057	3248 B	3.98
Cloudikka_PolylineEncoding_Decode	.NET 6.0	1,763.8 ns	4.51 ns	4.00 ns	1.38	0.01	3	0.4959	0.0019	3120 B	3.82
PolylineDecoder_Decode	.NET 6.0	1,277.5 ns	4.43 ns	4.14 ns	1.00	0.00	2	0.1297	-	816 B	1.00
Polyliner_Decode	.NET 6.0	837.2 ns	2.49 ns	2.21 ns	0.66	0.00	1	0.5169	0.0057	3248 B	3.98
Cloudikka_PolylineEncoding_Decode	.NET 7.0	1,387.6 ns	24.18 ns	22.62 ns	1.12	0.02	2	1.4915	-	3120 B	3.82
PolylineDecoder_Decode	.NET 7.0	1,237.5 ns	3.05 ns	2.86 ns	1.00	0.00	1	0.3891	-	816 B	1.00
Polyliner_Decode	.NET 7.0	1,230.6 ns	2.08 ns	1.84 ns	0.99	0.00	1	1.5526	-	3248 B	3.98
Cloudikka_PolylineEncoding_Decode	.NET 8.0	766.0 ns	3.39 ns	3.17 ns	1.49	0.01	3	1.4915	-	3120 B	3.82
PolylineDecoder_Decode	.NET 8.0	513.9 ns	1.21 ns	1.14 ns	1.00	0.00	1	0.3901	-	816 B	1.00
Polyliner_Decode	.NET 8.0	704.4 ns	1.38 ns	1.29 ns	1.37	0.00	2	1.5526	-	3248 B	3.98
Cloudikka_PolylineEncoding_Decode	.NET 9.0	782.5 ns	1.50 ns	1.33 ns	1.57	0.00	3	1.4915	-	3120 B	3.82
PolylineDecoder_Decode	.NET 9.0	498.7 ns	1.27 ns	1.19 ns	1.00	0.00	1	0.3901	-	816 B	1.00
Polyliner_Decode	.NET 9.0	705.2 ns	1.30 ns	1.15 ns	1.41	0.00	2	1.5526	-	3248 B	3.98

Encode

BenchmarkDotNet v0.14.0, Windows 11 (10.0.26100.2894)
Apple Silicon, 4 CPU, 4 logical and 4 physical cores
.NET SDK 9.0.102
  [Host]     : .NET 9.0.1 (9.0.124.61010), Arm64 RyuJIT AdvSIMD
  Job-CJKHIS : .NET 5.0.17 (5.0.1722.21314), Arm64 RyuJIT AdvSIMD
  Job-GAHPKM : .NET 6.0.36 (6.0.3624.51421), Arm64 RyuJIT AdvSIMD
  Job-KWIIGA : .NET 7.0.20 (7.0.2024.26716), Arm64 RyuJIT AdvSIMD
  Job-ZMWUEM : .NET 8.0.12 (8.0.1224.60305), Arm64 RyuJIT AdvSIMD
  Job-EQIHVN : .NET 9.0.1 (9.0.124.61010), Arm64 RyuJIT AdvSIMD

Method	Runtime	Mean	Error	StdDev	Ratio	RatioSD	Rank	Gen0	Gen1	Allocated	Alloc Ratio
Cloudikka_PolylineEncoding_Encode	.NET 5.0	8,936.5 ns	26.81 ns	25.07 ns	8.18	0.04	3	2.2583	-	13.91 KB	7.95
PolylineEncoder_Encode	.NET 5.0	1,092.4 ns	4.73 ns	4.42 ns	1.00	0.01	1	0.2842	-	1.75 KB	1.00
Polyliner_Encode	.NET 5.0	1,291.0 ns	4.05 ns	3.16 ns	1.18	0.01	2	0.3643	0.0019	2.23 KB	1.28
Cloudikka_PolylineEncoding_Encode	.NET 6.0	7,640.7 ns	21.80 ns	20.39 ns	7.56	0.04	3	2.2583	-	13.91 KB	7.95
PolylineEncoder_Encode	.NET 6.0	1,011.3 ns	4.33 ns	4.05 ns	1.00	0.01	1	0.2842	-	1.75 KB	1.00
Polyliner_Encode	.NET 6.0	1,080.0 ns	3.35 ns	3.13 ns	1.07	0.01	2	0.3643	0.0019	2.23 KB	1.28
Cloudikka_PolylineEncoding_Encode	.NET 7.0	6,718.0 ns	13.77 ns	12.88 ns	6.65	0.02	3	6.8054	-	13.91 KB	7.95
PolylineEncoder_Encode	.NET 7.0	1,010.1 ns	3.32 ns	3.11 ns	1.00	0.00	1	0.8564	-	1.75 KB	1.00
Polyliner_Encode	.NET 7.0	1,075.9 ns	3.27 ns	2.73 ns	1.07	0.00	2	1.0929	-	2.23 KB	1.28
Cloudikka_PolylineEncoding_Encode	.NET 8.0	4,969.5 ns	9.29 ns	8.24 ns	9.53	0.03	3	6.8054	-	13.91 KB	7.95
PolylineEncoder_Encode	.NET 8.0	521.4 ns	1.37 ns	1.28 ns	1.00	0.00	1	0.8564	-	1.75 KB	1.00
Polyliner_Encode	.NET 8.0	1,020.7 ns	2.90 ns	2.57 ns	1.96	0.01	2	1.0929	-	2.23 KB	1.28
Cloudikka_PolylineEncoding_Encode	.NET 9.0	3,809.8 ns	27.85 ns	26.06 ns	7.21	0.05	3	4.3335	-	8.86 KB	5.06
PolylineEncoder_Encode	.NET 9.0	528.2 ns	1.85 ns	1.73 ns	1.00	0.00	1	0.8564	-	1.75 KB	1.00
Polyliner_Encode	.NET 9.0	1,033.9 ns	6.30 ns	5.89 ns	1.96	0.01	2	1.0929	-	2.23 KB	1.28

Documentation

Documentation is can be found at https://dropoutcoder.github.io/polyline-algorithm-csharp/api/index.html.

Happy coding!