shadow.rs

1use crate::design::BASE;2use mrlymath::bang::factory::residue_corners;34pub fn digits() -> Vec<[i64; 3]> {5    residue_corners(3, BASE)6        .into_iter()7        .filter(|corner| corner.iter().filter(|digit| **digit == 1).count() <= 1)8        .map(|corner| [corner[0] as i64, corner[1] as i64, corner[2] as i64])9        .collect()10}1112pub fn cube_digits() -> Vec<[i64; 3]> {13    residue_corners(3, BASE)14        .into_iter()15        .map(|corner| [corner[0] as i64, corner[1] as i64, corner[2] as i64])16        .collect()17}1819fn gcd(a: i64, b: i64) -> i64 {20    if b == 0 {21        a.abs()22    } else {23        gcd(b, a % b)24    }25}2627pub fn primitive(v: [i64; 3]) -> bool {28    gcd(gcd(v[0], v[1]), v[2]) == 129}3031pub fn shadow(level: usize, view: [i64; 3], digits: &[[i64; 3]]) -> usize {32    let count = digits.len();33    let total = count.pow(level as u32);34    let side = (BASE as i64).pow(level as u32);35    let span = 4 * side * 3 + 4;36    let mut keys: Vec<i64> = Vec::with_capacity(total);37    for index in 0..total {38        let mut left = index;39        let mut point = [0i64; 3];40        for _ in 0..level {41            let digit = digits[left % count];42            left /= count;43            for axis in 0..3 {44                point[axis] = point[axis] * BASE as i64 + digit[axis];45            }46        }47        let cross = [48            point[1] * view[2] - point[2] * view[1],49            point[2] * view[0] - point[0] * view[2],50            point[0] * view[1] - point[1] * view[0],51        ];52        let key = ((cross[0] + span) * 2 * span + cross[1] + span) * 2 * span + cross[2] + span;53        keys.push(key);54    }55    keys.sort_unstable();56    keys.dedup();57    keys.len()58}5960pub fn views(bound: i64) -> Vec<[i64; 3]> {61    let mut out = Vec::new();62    for a in 0..=bound {63        for b in a..=bound {64            for c in b..=bound {65                if c == 0 || !primitive([a, b, c]) {66                    continue;67                }68                out.push([a, b, c]);69            }70        }71    }72    out73}