bendns' repos / cgol
simple conway thing
Diffstat (limited to 'src/main.rs')
-rw-r--r--src/main.rs133
1 files changed, 133 insertions, 0 deletions
diff --git a/src/main.rs b/src/main.rs
new file mode 100644
index 0000000..ae6773e
--- /dev/null
+++ b/src/main.rs
@@ -0,0 +1,133 @@
+use std::{
+ io::{self, Write},
+ time::Duration,
+};
+
+const WIDTH: usize = 50;
+const HEIGHT: usize = 20;
+pub struct Grid([[bool; HEIGHT + 2]; WIDTH + 2]);
+
+impl Default for Grid {
+ fn default() -> Self {
+ Self([[false; HEIGHT + 2]; WIDTH + 2])
+ }
+}
+
+impl Grid {
+ #[inline]
+ fn neighbors(&self, x: usize, y: usize) -> u8 {
+ let x = x + 1;
+ let y = y + 1;
+ macro_rules! n {
+ ($(($sx: tt $x: expr, $sy: tt $y: expr))+) => {{
+ let mut n = 0;
+ $(if self.0[n!(@ $sx $x + x)][n!(@ $sy $y + y)] {
+ n += 1;
+ })+
+ n
+ }};
+ (@ -$n:literal + $v: ident) => { $v - $n };
+ (@ +$n:literal + $v: ident) => { $v + $n };
+ }
+ n![(-1, -1)(+0, -1)(+1, -1)(-1, +0)(+1, +0)(-1, +1)(+0, +1)(+1, +1)]
+ }
+
+ #[inline]
+ fn kill(&mut self, x: usize, y: usize) {
+ self.set(x, y, false);
+ }
+
+ #[inline]
+ fn spawn(&mut self, x: usize, y: usize) {
+ self.set(x, y, true);
+ }
+
+ #[inline]
+ fn set(&mut self, x: usize, y: usize, to: bool) {
+ self.0[x + 1][y + 1] = to
+ }
+
+ #[inline]
+ fn cell(&self, x: usize, y: usize) -> bool {
+ self.0[x + 1][y + 1]
+ }
+
+ fn iterate(&mut self) {
+ let mut neighbors = [[0u8; HEIGHT + 2]; WIDTH + 2];
+
+ for x in 0..WIDTH {
+ for y in 0..HEIGHT {
+ neighbors[x + 1][y + 1] = self.neighbors(x, y);
+ }
+ }
+
+ for x in 0..WIDTH {
+ for y in 0..HEIGHT {
+ let cell = self.cell(x, y);
+ let n = neighbors[x + 1][y + 1];
+ match n {
+ 2 | 3 if cell => continue,
+ 3 if !cell => self.spawn(x, y),
+ _ => self.kill(x, y),
+ }
+ }
+ }
+ }
+
+ fn dead(&mut self) -> bool {
+ for row in self.0 {
+ for col in row {
+ if col {
+ return false;
+ };
+ }
+ }
+ true
+ }
+
+ fn print(&self, mut w: impl Write) -> io::Result<()> {
+ let tab = ["░░", "██"];
+ for y in 0..HEIGHT {
+ for x in 0..WIDTH {
+ w.write_all(tab[self.cell(x, y) as usize].as_bytes())?;
+ }
+ writeln!(w)?;
+ }
+ Ok(())
+ }
+}
+
+fn main() {
+ let mut grid = Grid::default();
+ let img = image::open("src/seed.png").unwrap().to_luma8();
+ assert!(img.width() == WIDTH as u32);
+ assert!(img.height() == HEIGHT as u32);
+ for x in 0..WIDTH {
+ for y in 0..HEIGHT {
+ let on = img.get_pixel(x as u32, y as u32)[0] <= 128;
+ grid.set(x, y, on);
+ }
+ }
+
+ while !grid.dead() {
+ print!("");
+ grid.print(std::io::stdout().lock()).unwrap();
+ grid.iterate();
+ std::thread::sleep(Duration::from_millis(100));
+ }
+}
+
+#[cfg(test)]
+mod tests {
+ use super::*;
+ #[test]
+ fn neb() {
+ let mut g = Grid::default();
+ assert_eq!(g.neighbors(0, 0), 0);
+ assert_eq!(g.neighbors(5, 5), 0);
+ g.spawn(5, 5);
+ assert_eq!(g.neighbors(4, 4), 1);
+ g.spawn(4, 5);
+ assert_eq!(g.neighbors(4, 4), 2);
+ }
+}