Triangulate

Triangulate is a Swift library for generating Delaunay triangulations using the Bowyer-Watson algorithm.

Installation

To install Triangulate, add it to your project using Swift Package Manager.

.package(url: "https://github.com/nicholascross/Triangulate", from: "0.0.1")

Usage

To generate a Delaunay triangulation, create a TriangleMesh instance and pass it a list of vertices:

let vertices = [
    simd_float2(x: 0, y: 0),
    simd_float2(x: 100, y: 0),
    simd_float2(x: 0, y: 100),
    simd_float2(x: 100, y: 100)
]
let mesh = TriangleMesh(vertices)

The indices property of the TriangleMesh instance will contain the indices of the triangles in the mesh, referencing the vertices in the vertices property.

For example to render the triangulation in a SwiftUI view, you can use the indices and vertices properties to draw the triangles using a Path as follows.

ZStack(alignment: .center) {
    ForEach(Array(stride(from: 0, to: self.mesh.indices.count, by: 3)), id: \.self) { i in
        Path { path in
            let index1 = self.mesh.indices[i]
            let vertex1 = self.mesh.vertices[index1]
            let index2 = self.mesh.indices[(i + 1)]
            let vertex2 = self.mesh.vertices[index2]
            let index3 = self.mesh.indices[(i + 2)]
            let vertex3 = self.mesh.vertices[index3]

            path.move(to: CGPoint(x: CGFloat(vertex1.x), y: CGFloat(vertex1.y)))
            path.addLine(to: CGPoint(x: CGFloat(vertex2.x), y: CGFloat(vertex2.y)))
            path.addLine(to: CGPoint(x: CGFloat(vertex3.x), y: CGFloat(vertex3.y)))
            path.closeSubpath()
        }
        .stroke(Color.red)
    }
}