Should the output function only be in the example file?

[elbert5770]

It seems kind of fragile to not have the output function in the main file, MarchingCubes.jl.

[t-bltg]

I don't really understand what you mean, could you clarify ?

[elbert5770]

"example.jl" implies a file that stores a simple example, and in fact this is the case (i.e. scenario()). However, the file also contains the following crucial functions, which aren't even used in the example. It seems like they should be in MarchingCubes.jl

output(PlyIO::Module, m::MC, fn::AbstractString = "test.ply") = begin
    ply = PlyIO.Ply()
    push!(
        ply,
        PlyIO.PlyElement(
            "vertex",
            PlyIO.ArrayProperty("x", map(v -> Float32(v[1]), m.vertices)),
            PlyIO.ArrayProperty("y", map(v -> Float32(v[2]), m.vertices)),
            PlyIO.ArrayProperty("z", map(v -> Float32(v[3]), m.vertices)),
            PlyIO.ArrayProperty("nx", map(n -> Float32(n[1]), m.normals)),
            PlyIO.ArrayProperty("ny", map(n -> Float32(n[2]), m.normals)),
            PlyIO.ArrayProperty("nz", map(n -> Float32(n[3]), m.normals)),
        ),
    )
    vertex_indices = PlyIO.ListProperty("vertex_indices", UInt8, Int32)
    for i ∈ eachindex(m.triangles)
        push!(vertex_indices, m.triangles[i] .- 1)
    end
    push!(ply, PlyIO.PlyElement("face", vertex_indices))

    PlyIO.save_ply(ply, fn, ascii = true)
    nothing
end

makemesh_Meshes(Meshes::Module, m::MC) = begin
    points = map(Meshes.Point3 ∘ Tuple, m.vertices)
    tris = Meshes.connect.(map(Tuple, m.triangles), Meshes.Triangle)
    Meshes.SimpleMesh(points, [tris;])
end

makemesh_GeometryBasics(GeometryBasics::Module, m::MC) = begin
    vertices = map(GeometryBasics.Point3f, m.vertices)
    normals = map(GeometryBasics.Vec3f, m.normals)
    triangles = map(t -> GeometryBasics.TriangleFace(t...), m.triangles)
    GeometryBasics.Mesh(GeometryBasics.meta(vertices; normals), triangles)
end

makemesh(mod::Module, m::MC) =
    if (mod_str = string(mod)) == "Meshes"
        makemesh_Meshes(mod, m)
    elseif mod_str == "GeometryBasics"
        makemesh_GeometryBasics(mod, m)
    else
        throw(ArgumentError("un-supported module `$mod`"))
    end

[t-bltg]

Those functions were solely added to show an example of using the MarchingCubes algorithm as a library.

Furthermore, they use modules arguments (e.g. PlyIO), without specifying any version constraints, and are hence not guaranteed to work in the future.

They are also related to how you visualize your computations, and since everyone has its own preferred graphics / plotting library, they are not universal.

This is why I don't think they should be part of the library.