here_be_dragons/demo/src/lib.rs

use wasm_bindgen::prelude::*;
use rand::prelude::*;
use mapgen::dungeon::{
    MapBuilder,
    map::TileType,
    cellular_automata::CellularAutomataGen,
    starting_point::{AreaStartingPosition, XStart, YStart},
    cull_unreachable::CullUnreachable,
    distant_exit::DistantExit,
};


#[wasm_bindgen]
#[repr(u8)]
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
pub enum Cell {
    Floor = 0,
    Wall = 1,
}

#[wasm_bindgen]
pub struct World {
    width: u32,
    height: u32,
    tiles: Vec<Cell>,
}

#[wasm_bindgen]
impl World {
    pub fn new_cellular_automata(width: u32, height: u32, seed: u32) -> World {
        let mut rng = StdRng::seed_from_u64(seed as u64);
        let map = MapBuilder::new(Box::new(CellularAutomataGen::new(width as usize, height as usize)))
            .with(AreaStartingPosition::new(XStart::CENTER, YStart::CENTER))
            .with(CullUnreachable::new())
            .with(DistantExit::new())
            .build_map_with_rng(&mut rng);
        let tiles = (0..map.tiles.len())
            .map(|i| if map.tiles[i] == TileType::Floor {Cell::Floor} else {Cell::Wall})
            .collect();
        World { 
            width,
            height,
            tiles }
    }

    pub fn width(&self) -> u32 {
        self.width
    }

    pub fn height(&self) -> u32 {
        self.height
    }

    pub fn tiles(&self) -> *const Cell {
        self.tiles.as_ptr()
    }
}