use std::marker::PhantomData;
use crate::MapFilter;
use crate::{
geometry::Point,
map::{Map, Tile},
random::Rng,
};
use rand::prelude::*;
pub struct VoronoiHive<D> {
n_seeds: usize,
phantom: PhantomData<D>,
}
impl<D: Clone + Default> MapFilter<D> for VoronoiHive<D> {
fn modify_map(&self, rng: &mut StdRng, map: &Map<D>) -> Map<D> {
self.build(rng, map)
}
}
impl<D: Clone + Default> VoronoiHive<D> {
pub fn new() -> Box<VoronoiHive<D>> {
Box::new(VoronoiHive {
n_seeds: 64,
phantom: PhantomData,
})
}
fn build(&self, rng: &mut StdRng, map: &Map<D>) -> Map<D> {
let mut new_map = map.clone();
let seeds = self.generate_seeds(rng, map.width, map.height);
let mut voronoi_distance = vec![(0, 0.0f32); self.n_seeds];
let mut voronoi_membership: Vec<i32> = vec![0; map.width * map.height];
for (i, vid) in voronoi_membership.iter_mut().enumerate() {
let x = i % map.width;
let y = i / map.width;
for (seed, pos) in seeds.iter().enumerate() {
let distance = pos.distance_to(&Point::new(x, y));
voronoi_distance[seed] = (seed, distance);
}
voronoi_distance.sort_by(|a, b| a.1.partial_cmp(&b.1).unwrap());
*vid = voronoi_distance[0].0 as i32;
}
for y in 1..new_map.height - 1 {
for x in 1..new_map.width - 1 {
let mut neighbors = 0;
let my_idx = new_map.xy_idx(x, y);
let my_seed = voronoi_membership[my_idx];
if voronoi_membership[new_map.xy_idx(x - 1, y)] != my_seed {
neighbors += 1;
}
if voronoi_membership[new_map.xy_idx(x + 1, y)] != my_seed {
neighbors += 1;
}
if voronoi_membership[new_map.xy_idx(x, y - 1)] != my_seed {
neighbors += 1;
}
if voronoi_membership[new_map.xy_idx(x, y + 1)] != my_seed {
neighbors += 1;
}
if neighbors < 2 {
new_map.set_tile(x, y, Tile::floor());
}
}
}
new_map
}
fn generate_seeds(&self, rng: &mut StdRng, width: usize, height: usize) -> Vec<Point> {
let mut seeds: Vec<Point> = Vec::new();
while seeds.len() < self.n_seeds {
let vx = rng.roll_dice(1, width - 1);
let vy = rng.roll_dice(1, height - 1);
let candidate = Point::new(vx, vy);
if !seeds.contains(&candidate) {
seeds.push(candidate);
}
}
seeds
}
}