## Shadowcaster

This is an implementation of recursive shadowcasting for use in grid based video games.

### Example Usage

#### Bevy

```Rust
/// Bevy requires any static data to implement Resource, so you can easily use that across the app
#[derive(Resource)]
pub struct VisContainer {
  pub visibility: shadowcaster::Visibility,
}

/// update the observer as the player moves
pub fn player_transform_system(
  mut commands: Commands,
  player_query: Query<&Transform, With<Player>>,
) {
    if player_query.get_single().is_err() {
        return;
    }
    let player_transform = player_query.single();
    vis_container.visibility.observer = player_grid_pos;
}
```
