# geo-visibility

This crate contains algorithms to compute [visibility polygon](https://www.wikiwand.com/en/Visibility_polygon).

[![crate.io](https://img.shields.io/crates/v/geo-visibility.svg)](https://crates.io/crates/geo-visibility)
[![docs.rs](https://docs.rs/geo-visibility/badge.svg)](https://docs.rs/geo-visibility)

This code is a Rust port of the C++ lib [visibility](https://github.com/trylock/visibility).

## Example

The following example shows how to compute the visibility polygon of a point amongst line obstacles.
The [`visibility`] method is provided by the [`Visibility`] trait which is implemented for most [geo-types](https://docs.rs/geo-types/0.4.3/geo_types/).

```rust
use geo::{Coordinate, Line};
use geo_visibility::Visibility;

let point = geo::Point::new(0.0, 0.0);

let lines = vec![
    Line::new(
        Coordinate { x: 1.0, y: 1.0 },
        Coordinate { x: 1.0, y: -1.0 },
    ),
    Line::new(
        Coordinate { x: -1.0, y: -1.0 },
        Coordinate { x: -1.0, y: -2.0 },
    ),
];

let visibility_polygon = point.visibility(lines.as_slice());
```

[`Visibility`]: visibility/trait.Visibility.html
[`visibility`]: visibility/trait.Visibility.html#method.visibility