Slow down chars mode.

src/bin/chars/main.rs

@@ -62,6 +62,7 @@ fn main() -> std::io::Result<()> {
     .take(y_size)
     .collect::<Vec<_>>();
     loop {
+        if rng.gen::<f64>() < 0.01 {
             let x = rng.gen_range(0, x_size / 8);
             let y = rng.gen_range(0, y_size / 8);
             let color = pick_color(c0, c1, &mut rng);
@@ -78,6 +79,7 @@ fn main() -> std::io::Result<()> {
                     };
                 }
             }
+        }
 
         let mut buf = Vec::with_capacity(x_size * y_size * 3);
         send(&mut buf, &frame)?;