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. The demo covers operations like union, intersection, difference and exclusion

• 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.

Working Range and Precision

The i_overlay library operates within the following ranges and precision levels:

Extended Range: From -1,000,000 to 1,000,000 with a precision of 0.001. Recommended Range: From -100,000 to 100,000 with a precision of 0.01 for more accurate results. Utilizing the library within the recommended range ensures optimal accuracy in computations and is advised for most use cases.

Getting Started

Add the following to your Cargo.toml:

[dependencies]
i_float
i_shape
i_overlay

Example

Here is a simple example that demonstrates how to use the iOverlay library for polygon union operations.

use i_float::fix_vec::FixVec;
use i_overlay::{layout::overlay::Overlay, fill::shape_type::ShapeType, bool::fill_rule::FillRule};

fn main() {
    let mut overlay = Overlay::new(1);
        
    let subj = [
        FixVec::new_number(-10, -10),
        FixVec::new_number(-10,  10),
        FixVec::new_number( 10,  10),
        FixVec::new_number( 10, -10)
    ];

    let clip = [
        FixVec::new_number(-5, -5),
        FixVec::new_number(-5, 15),
        FixVec::new_number(15, 15),
        FixVec::new_number(15, -5)
    ];

    overlay.add_path(subj.to_vec(), ShapeType::SUBJECT);
    overlay.add_path(clip.to_vec(), ShapeType::CLIP);

    let graph = overlay.build_graph();

    let shapes = graph.extract_shapes(FillRule::Union);

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

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

Union

Difference

Intersection

Exclusion (xor)

Self-intersection