[BUG]: Failing to calculate polygons for a voronoi plot

[maltepuetz]

Describe the bug

The calculation of polygons for a voronoi plot fails for a specific choice of points (i.e. a grid on a triangle). The issue is inside grow_polygon_outside_of_box, where the function returns Inf. I have implemented a workaround locally and will create a PR which I will link to this issue.

Reproducer

You can reproduce the issue when trying to do a voronoi plot as below:

using CairoMakie
using LinearAlgebra

function generatePoints(n)
    points = Vector{NTuple{3,Float64}}(undef, n * (n + 1) ÷ 2)
    m = 1
    for (k, i) in enumerate(range(0, 1, n))
        for j in range(i, 1, n - k + 1)
            px = i
            py = j - i
            pz = 1 - j
            points[m] = (px, py, pz)
            m += 1
        end
    end
    return points
end
function projection(point; origin=[1 / 3, 1 / 3, 1 / 3], e1=normalize(cross(normalize([0.0, 0.0, 1.0] .- [1 / 3, 1 / 3, 1 / 3]), normalize([1 / 3, 1 / 3, 1 / 3]))), e2=normalize([0.0, 0.0, 1.0] .- [1 / 3, 1 / 3, 1 / 3]))
    return sum(e1 .* (point .- origin)), sum(e2 .* (point .- origin))
end

points = generatePoints(3)
points2d = [projection(p) for p in points]
voronoiplot([p[1] for p in points2d], [p[2] for p in points2d], randn(size(points2d)))

Environment information

using InteractiveUtils
versioninfo()

Julia Version 1.12.2
Commit ca9b6662be4 (2025-11-20 16:25 UTC)
Build Info:
Official https://julialang.org release
Platform Info:
OS: macOS (arm64-apple-darwin24.0.0)
CPU: 12 × Apple M3 Pro
WORD_SIZE: 64
LLVM: libLLVM-18.1.7 (ORCJIT, apple-m3)
GC: Built with stock GC
Threads: 1 default, 1 interactive, 1 GC (on 6 virtual cores)
Environment:
JULIA_EDITOR = code

and

using Pkg
Pkg.status()

Status /private/var/folders/bb/tp8g2s_95jb3x146dfglhw_h0000gn/T/jl_CI63nn/Project.toml
[13f3f980] CairoMakie v0.15.7