Merge pull request 'modify seeding 2 b portable and reproducible' (#1) from barrow/codename-routes:main into main

Reviewed-on: https://git.kittycat.homes/zoe/codename-routes/pulls/1

routes-native/Cargo.toml

@@ -13,8 +13,9 @@ gdnative = {version = "0.10", features = ["async"]}
 strum = { version = "0.24", features = ["derive"] }
 strum_macros = "0.24"
 derive_builder = "0.11.2"
-rand_seeder = "0.2.3"
 rand = "0.8.5"
+rand_xoshiro = "0.6"
+blake3 = "1" # 1.3.1 at time of addition
 toml = "0.5.9"
 noise = "0.7.0"
 

routes-native/src/stateserver/world/gen.rs

@@ -1,13 +1,21 @@
-use rand::{prelude::StdRng, Rng};
-use noise::{Seedable, utils::{PlaneMapBuilder, NoiseMapBuilder, NoiseMap}, SuperSimplex};
-use rand_seeder::Seeder;
+use noise::{
+    utils::{NoiseMap, NoiseMapBuilder, PlaneMapBuilder},
+    Seedable, SuperSimplex,
+};
+use rand::{Rng, SeedableRng};
 
-pub fn get_rng(seed: String) -> StdRng{
-    Seeder::from(seed).make_rng()
+pub type GameRng = rand_xoshiro::Xoshiro256PlusPlus;
+
+pub fn get_rng(seed: impl AsRef<[u8]> /* implemented by String */) -> GameRng {
+    // blake3::Hash is a [u8; 32] under the hood and implements From and Into to convert to and from it
+    let hash: [u8; 32] = blake3::hash(seed.as_ref()).into();
+    // Xoshiro256++ seeds are [u8; 32] :3
+    GameRng::from_seed(hash)
 }
 
-pub fn get_noise(rng: &mut StdRng, size: (usize, usize)) -> NoiseMap{
-    let noise = SuperSimplex::new().set_seed(rng.gen_range(0..u32::MAX));
+pub fn get_noise(rng: &mut GameRng, size: (usize, usize)) -> NoiseMap {
+    // rng.gen::<u32>() generates a random u32 which is already between 0 and u32::MAX
+    let noise = SuperSimplex::new().set_seed(rng.gen());
     PlaneMapBuilder::new(&noise)
         .set_size(size.0, size.1)
         .build()