Cheap and dirty RNGs

use voxell_rng::prelude::*;
use voxell_rng::time_seeded::TimeSeededXorShift32;
// seeds using os entropy
let mut rng = TimeSeededXorShift32::generate().unwrap();
rng.next_u32();

Welcome to the land of unreproducible builds

Use this crate if you need simple random number generators for your project and you don't want to depend on a big library like rand.

You can seed your RNGs using the system time [voxell_rng::time_seeded] or runtime entropy [voxell_rng::runtime_seeded].

There are 5 RNGs available:

• SplitMix64: a 64-bit RNG with 64-bit output used for seeding other RNGs
• XorShift32: a 32-bit Xorshift RNG with 32-bit output
• XorShift128: a 128-bit Xorshift RNG with 64-bit output (Recommended)
• XoRoShiRo128: a 128-bit XoRoShiRo RNG with 64-bit output
• Pcg8 through Pcg128: the PCG family of RNGs

All RNGs implement BranchRng which is a simple trait that provides a branch_rng method for creating a new divergent RNG from the current one. The resulting RNG will have a different state and will produce different random numbers without needing to specify a new seed.

Examples

1. Create a new RNG using a constant seed and use it:

use voxell_rng::rng::XorShift32;

// create the rng
let mut rng = XorShift32::new(0xcafebabe as u64);

// generate a new number
rng.next_f32();

2. Seed your RNGs using the system time

use voxell_rng::time_seeded::TimeSeededXorShift32;
let mut rng = TimeSeededXorShift32::generate().unwrap();
rng.next_f32();

3. Seed your RNGs using runtime entropy

use voxell_rng::rng::XorShift32;
// Default implementation for non-PCG RNG's use OS entropy
let mut rng = XorShift32::default();
rng.next_f32();

4. Create new RNGs from a master RNG for divergent thread local RNGs:

use voxell_rng::prelude::*;
use voxell_rng::rng::XoRoShiRo128;

let mut master_rng = XoRoShiRo128::new(0xabad1dea as u64);
let thread_handles = (0..16)
    .map(|_| {
        let rng = master_rng.branch_rng();
        std::thread::spawn(move || {
            let mut thread_local_rng = rng;
            for _ in 0..1000 {
                thread_local_rng.next_u64();
            }
        })
    })
    .collect::<Vec<_>>();