calda/CGPathIntersection

:curly_loop: A library that identifies points where two CGPaths intersect

Installation

Swift Package Manager

Add the following dependency to your package definition:

.package(
  name: "CGPathIntersection",
  url: "https://github.com/calda/CGPathIntersection.git",
  from: "4.0.0")

Carthage

Add github "calda/CGPathIntersection" to your Cartfile

CocoaPods

Add pod 'CGPathIntersection' to your Podfile

Usage

import CGPathIntersection

let path1 = CGPath(...)
let path2 = CGPath(...)
        
path1.intersects(path2) // returns a boolean
path1.intersectionPoints(with: path2) // returns an array of points

If performing many calculations, you can increase performance by creating a CGPathImage. Any calculations performed on a pre-existing CGPathImage will run faster than the same calculation performed on a raw CGPath.

import CGPathIntersection

let pathImage = CGPathImage(from: CGPath(...))
let otherPathImages: [CGPathImage] = [...]

let intersectingPaths = otherPathImages.filter { pathImage.intersects($0) }

Example

CGPathIntersection was created as a component of Streets, a prototype SpriteKit game that simulates managing a network of streets. Streets uses CGPathIntersection to connect individual roads together with physical intersections. When a car reaches an intersection, it makes a random turn onto one of the other connected roads.

Streets also has some support for more complex paths, like roundabouts:

Package Metadata

Repository: calda/CGPathIntersection

Stars: 67

Forks: 5

Open issues: 0

Default branch: master

Primary language: swift

License: MIT

Topics: core-graphics, intersection, ios, swift

README: README.md