5 releases (breaking)
0.5.0 | Feb 6, 2023 |
---|---|
0.4.0 | Feb 5, 2023 |
0.3.0 | Feb 4, 2023 |
0.2.0 | Jan 25, 2023 |
0.1.0 | Jan 24, 2023 |
#788 in Math
56 downloads per month
Used in esvg
38KB
886 lines
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(¢er))
.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
- Polygon unions
Wanted Features
Things we want to implement but haven't yet.
- Scale of points
- Scale of polygons
- 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.
Design goals
- Correct
- Safe
- Fast
In that order
Limitations / Warnings
Polygons must be specified with the points going clockwise around them. Several algorithms only work when points are defined clockwise. There is no detection of this, it will probably cause weird results, it has not been tested.
Dependencies
~45KB