ishape-rust / ioverlay

Boolean Operations for 2D Polygons: Supports intersection, union, difference, xor, and self-intersections for all polygon varieties.

iOverlay

The iOverlay is a fast poly-bool library supporting main operations like union, intersection, difference, and xor, governed by either the even-odd or non-zero rule. This algorithm is based on Vatti clipping ideas but is an original implementation.

Documentation

Try out iOverlay with an interactive demo:

• Stars Rotation
• Shapes Editor

Features

• Operations: union, intersection, difference, and exclusion.
• Polygons: with holes, self-intersections, and multiple paths.
• Simplification: removes degenerate vertices and merges collinear edges.
• Fill Rules: even-odd and non-zero.

Getting Started

Add the following to your Cargo.toml:

[dependencies]
i_float = "^1.0.0"
i_overlay = "^1.0.0"

Hello world

Let's union two squares

let subj = [
    F64Point::new(-10.0, -10.0),
    F64Point::new(-10.0, 10.0),
    F64Point::new(10.0, 10.0),
    F64Point::new(10.0, -10.0),
];

let clip = [
    F64Point::new(-5.0, -5.0),
    F64Point::new(-5.0, 15.0),
    F64Point::new(15.0, 15.0),
    F64Point::new(15.0, -5.0),
];

let mut overlay = FloatOverlay::new();

overlay.add_path(&subj, ShapeType::Subject);
overlay.add_path(&clip, ShapeType::Clip);

let graph = overlay.build_graph(FillRule::NonZero);
let shapes = graph.extract_shapes(OverlayRule::Union);

println!("shapes count: {}", shapes.len());

if shapes.len() > 0 {
    let contour = &shapes[0][0];
    println!("shape 0 contour: ");
    for p in contour {
        let x = p.x;
        let y = p.y;
        println!("({}, {})", x, y);
    }
}

Overlay Rules

Union, A or B

Intersection, A and B

Difference, B - A

Exclusion, A xor B

ioverlay's Issues

Docs?

I get that you have some interactive docs in https://ishape-rust.github.io/iShape-js/overlay/stars_demo.html but right now you have ZERO comments in your code. When I use a lib it would be nice to at least know just a line or two what a function does or what an enum is. Like wth is ShapeType?? and what is the difference between Subject and Clip??

A simple /** explain here */ or /// before the enum or function would make it much easier to follow when coding as you get that as an editor hint. It does not need to be an essay, but just something.