monte-carlo/src/random.rs

use std::fs::File;
use std::io::BufReader;
use std::io::Read;

// ┏━┓┏━┓┏┓╻╺┳┓┏━┓┏┳┓   ┏┓╻╻ ╻┏┳┓┏┓ ┏━╸┏━┓   ┏━╸┏━╸┏┓╻┏━╸┏━┓┏━┓╺┳╸╻┏━┓┏┓╻
// ┣┳┛┣━┫┃┗┫ ┃┃┃ ┃┃┃┃   ┃┗┫┃ ┃┃┃┃┣┻┓┣╸ ┣┳┛   ┃╺┓┣╸ ┃┗┫┣╸ ┣┳┛┣━┫ ┃ ┃┃ ┃┃┗┫
// ╹┗╸╹ ╹╹ ╹╺┻┛┗━┛╹ ╹   ╹ ╹┗━┛╹ ╹┗━┛┗━╸╹┗╸   ┗━┛┗━╸╹ ╹┗━╸╹┗╸╹ ╹ ╹ ╹┗━┛╹ ╹

pub struct RNG {
    random_device: BufReader<File>,
}

impl RNG {
    pub fn next_float(&mut self) -> f32 {
        let mut buf: [u8; 4] = [0, 0, 0, 0];

        self.random_device
            .read(&mut buf)
            .expect("Read from /dev/random failed");
        let val: f32 = u32::from_be_bytes(buf) as f32;
        f32::from(val) / (u32::max_value() as f32 + 1.0)
    }

    pub fn create() -> RNG {
        let f = File::open("/dev/urandom").expect("Did not find source of randomness");
        let reader: BufReader<File> = BufReader::new(f);

        return RNG {
            random_device: reader,
        };
    }
}