here_be_dragons/src/filter/noise_generator.rs

72 lines
1.8 KiB
Rust

//! Apply noise to the map.
//! Each cell will be set to Floor with the given probabilty.
//!
//! Example usage:
//! ```
//! use rand::prelude::*;
//! use here_be_dragons::{Map, MapFilter, NoData};
//! use here_be_dragons::filter::NoiseGenerator;
//!
//! let mut rng = StdRng::seed_from_u64(100);
//! let gen = NoiseGenerator::<NoData>::uniform();
//! let map = gen.modify_map(&mut rng, &Map::new(80, 50));
//!
//! assert_eq!(map.width, 80);
//! assert_eq!(map.height, 50);
//! ```
//!
use std::marker::PhantomData;
use crate::MapFilter;
use crate::{Map, Tile};
use rand::prelude::*;
/// Map noise generator
pub struct NoiseGenerator<D> {
prob: f32,
phantom: PhantomData<D>,
}
impl<D: Clone + Default> MapFilter<D> for NoiseGenerator<D> {
fn modify_map(&self, rng: &mut StdRng, map: &Map<D>) -> Map<D> {
self.build(map, rng)
}
}
impl<D: Clone + Default> NoiseGenerator<D> {
/// Create noise with custom probability
pub fn new(prob: f32) -> Box<NoiseGenerator<D>> {
Box::new(NoiseGenerator {
prob,
phantom: PhantomData,
})
}
/// Create uniform noise (Probablity 0.5)
pub fn uniform() -> Box<NoiseGenerator<D>> {
Box::new(NoiseGenerator {
prob: 0.5,
phantom: PhantomData,
})
}
/// Generate map
fn build(&self, map: &Map<D>, rng: &mut StdRng) -> Map<D> {
let mut new_map = map.clone();
let p = (self.prob * 100.0) as u32;
for y in 1..new_map.height - 1 {
for x in 1..new_map.width - 1 {
let roll = rng.next_u32() % 100;
if roll > p {
new_map.set_tile(x, y, Tile::floor())
} else {
new_map.set_tile(x, y, Tile::wall())
}
}
}
new_map
}
}