https://github.com/luizzak/libtessswift

Libtess2 tesselation/triangulation library wrapper for Swift
https://github.com/luizzak/libtessswift

cocoapod swift tesselation triangulation

Last synced: 9 days ago
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Libtess2 tesselation/triangulation library wrapper for Swift

• Host: GitHub
• URL: https://github.com/luizzak/libtessswift
• Owner: LuizZak
• License: mit
• Created: 2017-02-28T15:20:42.000Z (over 7 years ago)
• Default Branch: master
• Last Pushed: 2020-03-24T10:43:37.000Z (over 4 years ago)
• Last Synced: 2024-03-15T07:03:33.490Z (8 months ago)
• Topics: cocoapod, swift, tesselation, triangulation
• Language: C
• Homepage:
• Size: 685 KB
• Stars: 15
• Watchers: 5
• Forks: 8
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# LibTessSwift

[![Build Status](https://dev.azure.com/luiz-fs/LibTessSwift/_apis/build/status/LuizZak.LibTessSwift?branchName=master)](https://dev.azure.com/luiz-fs/LibTessSwift/_build/latest?definitionId=1&branchName=master)

A Swift wrapper on top of [Libtess2](https://github.com/memononen/Libtess2) for polygon triangulation.

Tests where derived from [LibTessDotNet](https://github.com/speps/LibTessDotNet) library, which is also a port of the library above.

Also, a fix for an issue of 0-area polygons from libtess2 that was fixed by LibTessDotNet is also merged in. 

Supports self-intersecting polygons and polygons with holes.

## Sample Usage

This is a sample wrapper over TessC to process polygons and return resultin vertices/indices pairs.

```swift

func process(polygon: [MyVector]) throws -> (vertices: [MyVector], indices: [Int])? {

    let polygon: [MyVector] = ... // This should be an array of vertices - must have at least an `x` and `y` coordinate pairs!

    guard let tess = TessC() else {

        print("Something went wrong while initializing TessC! :c")

        return nil

    }

    // Size of polygon (number of points per face)

    let polySize = 3

    // Map from MyVector to CVector3 (LibTessSwift's vector representation)

    let contour = polygon.map {

        CVector3(x: TESSreal($0.x), y: TESSreal($0.y), z: 0.0)

    }

    // Add the contour to LibTess

    tess.addContour(contour)

    // Tesselate - if no errors are thrown, we're good!

    try tess.tessellate(windingRule: .evenOdd, elementType: .polygons, polySize: polySize)

    // Collect resulting vector

    var result: [MyVector] = []

    var indices: [Int] = []

    

    // Extract vertices

    for vertex in tess.vertices! {

        result.append(MyVector(x: vertex.x, y: vertex.y))

    }

    

    // Extract each index for each polygon triangle found

    for i in 0..