rules.rs

1pub const RULES: usize = 256;23pub fn output(rule: usize, l: u8, c: u8, r: u8) -> u8 {4    ((rule >> (4 * l as usize + 2 * c as usize + r as usize)) & 1) as u85}67pub struct Diagram {8    pub steps: usize,9    pub width: usize,10    pub cells: Vec<u8>,11}1213impl Diagram {14    pub fn at(&self, t: usize, i: usize) -> u8 {15        self.cells[t * self.width + i]16    }17    pub fn centre(&self) -> usize {18        self.width / 219    }20    pub fn signed(&self, t: usize, offset: i64) -> u8 {21        let i = self.centre() as i64 + offset;22        if i < 0 || i >= self.width as i64 {23            024        } else {25            self.at(t, i as usize)26        }27    }28}2930pub fn evolve(rule: usize, steps: usize, pad: usize) -> (Diagram, u8) {31    let window = 2 * steps + 1;32    let width = window + 2 * pad;33    let mut cells = vec![0u8; (steps + 1) * width];34    cells[width / 2] = 1;35    let mut seen = 0u8;36    for t in 0..steps {37        for i in 0..width {38            let l = if i == 0 { 0 } else { cells[t * width + i - 1] };39            let c = cells[t * width + i];40            let r = if i + 1 == width {41                042            } else {43                cells[t * width + i + 1]44            };45            seen |= 1 << (4 * l + 2 * c + r);46            cells[(t + 1) * width + i] = output(rule, l, c, r);47        }48    }49    for i in 0..width {50        let l = if i == 0 {51            052        } else {53            cells[steps * width + i - 1]54        };55        let c = cells[steps * width + i];56        let r = if i + 1 == width {57            058        } else {59            cells[steps * width + i + 1]60        };61        seen |= 1 << (4 * l + 2 * c + r);62    }63    let mut cropped = vec![0u8; (steps + 1) * window];64    for t in 0..=steps {65        cropped[t * window..(t + 1) * window]66            .copy_from_slice(&cells[t * width + pad..t * width + pad + window]);67    }68    (69        Diagram {70            steps,71            width: window,72            cells: cropped,73        },74        seen,75    )76}7778pub fn single_seed(rule: usize, steps: usize) -> Diagram {79    evolve(rule, steps, steps).080}8182pub fn mirrored(diagram: &Diagram) -> Vec<u8> {83    let mut out = vec![0u8; diagram.cells.len()];84    for t in 0..=diagram.steps {85        for i in 0..diagram.width {86            out[t * diagram.width + i] = diagram.at(t, diagram.width - 1 - i);87        }88    }89    out90}