Getting started

The kernel is not on crates.io yet. Depend on it by git:

[dependencies]
ogeom = { git = "https://github.com/gilbertorconde/ogeom-rs" }

Use the ogeom umbrella crate. It re-exports the whole API as modules (ogeom::algo, ogeom::boolean, ogeom::topo, ogeom::io, …). The ogeom-* crates underneath are an implementation detail and their boundaries will change.

A first solid

A block with a hole through it: two primitives, one boolean, and a volume check.

    let mut model = Model::new();
    let tol = Tolerances::millimetres();

    // A 20×20×10 block, and a Ø8 hole through its middle.
    let block = ogeom::algo::make_box(&mut model, Frame::WORLD, (20.0, 20.0, 10.0), tol)
        .unwrap()
        .shape;
    let axis = Frame::new(Point::new(10.0, 10.0, 0.0), Direction::Z, Direction::X, tol).unwrap();
    let drill = ogeom::algo::make_cylinder(&mut model, axis, 4.0, 10.0, tol)
        .unwrap()
        .shape;
    let part = ogeom::boolean::cut(&mut model, &block, &drill, tol)
        .unwrap()
        .shape;

    // The result is measured, not assumed: volume against the closed form.
    let volume = ogeom::algo::volume_properties(&model, &part, Deflection::default(), tol)
        .unwrap()
        .mass;
    let exact = 20.0 * 20.0 * 10.0 - core::f64::consts::PI * 4.0 * 4.0 * 10.0;
    assert!((volume - exact).abs() / exact < 0.01);

The same patterns apply to the whole API:

• Model owns all data. Geometry, topology, tolerances and history live in one Model. Operations take &mut model. A Shape is a cheap handle into the model; copying it copies no geometry. See the data model.
• Every operation takes a Tolerances. There is no global epsilon. Tolerances::millimetres() is the preset for models in millimetres. See Tolerances.
• Every operation returns a Built. built.shape is the result. The rest of Built is the history: which input entities generated or were modified into which outputs. Every operation fills it in, so parametric applications can rely on it.
• Errors are values. Everything returns Result. When the kernel cannot produce a correct result, it returns a named refusal instead of bad geometry.