Simplify-Swift 1.1.0

Simplify-Swift 1.1.0

Maintained by Tomislav Filipcic.


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Simplify-Swift is a high-performance Swift polyline simplification library ported from Simplify.js. The original Javascript library was extracted from Leaflet, a JS interactive maps library by Vladimir Agafonkin. It uses a combination of Douglas-Peucker and Radial Distance algorithms.

Polyline simplification dramatically reduces the number of points in a polyline while retaining its shape, giving a huge performance boost when processing it and also reducing visual noise. For example, it's essential when rendering a large polyline in MapKit.

Simplify-Swift screenshot


To run the example project, clone the repo, and run pod install from the Example directory first.


Simplify-Swift is available through CocoaPods. To install it, simply add the following line to your Podfile:

pod 'Simplify-Swift'


class func simplify<T:SimplifyValue>(_ points: [T], tolerance: Float?, highQuality: Bool = false) -> [T]

Returns an array of simplified points

  • parameter points: An array of points of SimplifyValue {x: Double, y: Double} format. Generics are supported so you can pass in an array of [CGPoint] or [CLLocationCoordinate2D].
  • parameter tolerance: Affects the amount of simplification (in the same metric as the point coordinates). Default: 1.
  • parameter highQuality: Excludes distance-based preprocessing step which leads to highest quality simplification but runs ~10-20 times slower. Default: false.


Tomislav Filipcic, [email protected], @tomislav


Simplify-Swift is available under the MIT license. See the LICENSE file for more info.