game of life example, bug fixes

examples/game_of_life/src/main.rs

@@ -0,0 +1,78 @@
+use std::thread;
+use std::time::Duration;
+use rand::{distributions, Rng};
+use clap::Parser;
+use servicepoint2::{Connection, Origin, PixelGrid};
+use servicepoint2::Command::BitmapLinearWin;
+
+#[derive(Parser, Debug)]
+struct Cli {
+    #[arg(short, long, default_value = "localhost:2342")]
+    destination: String,
+    #[arg(short, long, default_value_t = 0.5f64)]
+    probability: f64,
+}
+
+fn main() {
+    let cli = Cli::parse();
+    println!("starting with args: {:?}", &cli);
+
+    let connection = Connection::open(&cli.destination).unwrap();
+
+    let mut field = PixelGrid::max_sized();
+
+    let mut rng = rand::thread_rng();
+    let d = distributions::Bernoulli::new(cli.probability).unwrap();
+    for x in 0..field.width {
+        for y in 0..field.height {
+            field.set(x, y, rng.sample(d));
+        }
+    }
+
+    let origin = Origin(0, 0);
+    loop {
+        connection.send(BitmapLinearWin(origin, field.clone())).expect("could not send");
+        thread::sleep(Duration::from_millis(14));
+
+        let mut next = field.clone();
+
+        for x in 0..field.width {
+            for y in 0..field.height {
+                let old_state = field.get(x, y);
+                let neighbors = count_neighbors(&field, x as i32, y as i32);
+                let new_state = match (old_state, neighbors) {
+                    (true, 2) => true,
+                    (true, 3) => true,
+                    (false, 3) => true,
+                    _ => false
+                };
+                next.set(x, y, new_state);
+            }
+        }
+
+        field = next;
+    }
+}
+
+fn count_neighbors(field: &PixelGrid, x: i32, y: i32) -> i32 {
+    let mut count = 0;
+    for nx in x - 1..=x + 1 {
+        for ny in y - 1..=y + 1 {
+            if nx == x && ny == y {
+                continue; // the cell itself does not count
+            }
+
+            if nx < 0 || ny < 0 || nx >= field.width as i32 || ny >= field.height as i32 {
+                continue; // pixels outside the grid do not count
+            }
+
+            if !field.get(nx as usize, ny as usize) {
+                continue; // dead cells do not count
+            }
+
+            count += 1;
+        }
+    }
+
+    return count;
+}