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