Crate polygonical

Expand description

Polygonical

A library for interacting with polygons on a 2d plane.

Examples

Rotate a polygon:

    use polygonical::polygon::Polygon;
    use polygonical::point::Point;

    let poly = Polygon::new(vec![
        Point::new(0.0, 1.0),
        Point::new(1.0, 1.0),
        Point::new(1.0, 0.0),
    ]);

    // get the area of the polygon
    let area = poly.area();

    // rotate the polygon around its own center by 90 degrees
    let rotated = poly.rotate_around_center(90.0_f64.to_radians());

    println!("area: {} rotated: {}", area, rotated);

Create an approximation of a circle:

    use polygonical::polygon::Polygon;
    use polygonical::point::Point;

    let num_points = 16;
    let radius = 2.0;
    let center = Point::new(10.0, 20.0);

    // Note: we use an integer number of degrees here because rust won't let you iterate over floats like this.
    let points = (0..360).step_by(360/num_points)
        .map(|a| Point::new(radius, 0.0).rotate((a as f64).to_radians()).translate(center))
        .collect();

    let circle = Polygon::new(points);
     
    let approx_area = circle.area();
    let area = std::f64::consts::PI * radius * radius;

    println!("area: {} aprox_area: {} difference: {}", area, approx_area, area - approx_area);

Features

Points
Polygons
Bounding boxes
Translations of points
Polygons contain points
Polygon is_self_intersecting
Polygon area
Translations of polygons
Rotations of points
Rotations of polygons
Overlap detection
Contains detection

Wanted Features

Things we want to implement but haven’t yet.

Scale of points
Scale of polygons
Polygon unions
Polygon subtraction

Unwanted Features

Things this library won’t do.

3d Geometry
Output to things like svg (that is for another library)
Coordinate system transforms, epsg codes, pixel space to world space etc.

Polygons must be specified with the points going clockwise around them. Due to the way the contains point algorithm handles angles rolling over 360/0 degrees any function that relies on that algorithm will not work as expected.

Modules

boundingbox

point

polygon