Support for constructive geometry

[jondea]

As part of a FEM project I have implemented an Annulus<:Primitive type and several related functions. Does this count as a primitive, as in there isn't some clever way to make it from two balls? And if not, is this something that would be welcome for a PR?

[juliohm]

Hi @jondea thank you for proposing the primitive. I think what we really need is an API for constructive geometry. There are some packages out there already like

• https://github.com/plut/ConstructiveGeometry.jl
• https://github.com/JuliaGeometry/Descartes.jl

implementing subtraction, intersection and union of primitives. Ideally, we will be able to introduce these same operations in Meshes.jl reusing our primitive types to avoid inefficiencies with type conversion, and to help new users who just want to load a single ecosystem to get things done quickly.

[jondea]

Hi @juliohm, thank you for the pointers! That approach is certainly more elegant. I've made a branch with the Annulus type so I don't lose it https://github.com/jondea/Meshes.jl/tree/add-annulus-primitive, and I hope to be able to come back to this when I have more time.