An implementation of Adam Millazo's FOV algorithm

To use it you must implement the VisibilityMap trait on your map type, or use the built in VisibilityMap2d. Then you can call fov::compute with your map which will populate visible tiles based on the map's opaque tiles.

Example

```rust use adamfovrs::*;

// Create a 50x50 visibility map let mut map = VisibilityMap2d::default([50,50]);

// Set the tile at (15,15) to opaque map[[15,15]].opaque = true;

// Compute our visible tiles and add them to the map fov::compute([15,14], 5, &mut map);

// The space directly above our opaque tile is not visible assert!(map[[15,16]].visible == false); ```

Taken from the "terminal" example