From eff04faee4cbbcf3696a1ba7fe5709c27e2f8512 Mon Sep 17 00:00:00 2001
From: Juergen Stuber <juergen@jstuber.net>
Date: Fri, 28 Dec 2018 14:57:41 +0100
Subject: [PATCH] Preset colored noise.

---
 src/bin/cnoise/main.rs | 31 ++++++++++++++++++++-----------
 1 file changed, 20 insertions(+), 11 deletions(-)

diff --git a/src/bin/cnoise/main.rs b/src/bin/cnoise/main.rs
index 8a0a1f5..9c92213 100644
--- a/src/bin/cnoise/main.rs
+++ b/src/bin/cnoise/main.rs
@@ -1,7 +1,7 @@
 use std::env::args;
 use std::io::stdout;
 use std::io::Write;
-use std::iter::repeat;
+use std::iter::repeat_with;
 use std::thread::sleep;
 use std::time::Duration;
 
@@ -21,6 +21,17 @@ fn send<T: Write>(w: &mut T, f: &Frame) -> std::io::Result<()> {
     w.flush()
 }
 
+fn pick_color<R>(c0: Color, c1: Color, rng: &mut R) -> Color
+where
+    R: Rng,
+{
+    if rng.gen::<f64>() < 0.5 {
+        c0.interpolate(c1, rng.gen::<f64>().powf(2.0))
+    } else {
+        Color::black()
+    }
+}
+
 fn main() -> std::io::Result<()> {
     let args = args().collect::<Vec<_>>();
     eprintln!("executing {}", args[0]);
@@ -37,19 +48,17 @@ fn main() -> std::io::Result<()> {
 
     let mut rng = thread_rng();
 
-    let mut frame = repeat(repeat(Color::black()).take(x_size).collect::<Vec<_>>())
-        .take(y_size)
-        .collect::<Vec<_>>();
+    let mut frame = repeat_with(|| {
+        repeat_with(|| pick_color(c0, c1, &mut rng))
+            .take(x_size)
+            .collect::<Vec<_>>()
+    })
+    .take(y_size)
+    .collect::<Vec<_>>();
     loop {
         let x = rng.gen_range(0, x_size);
         let y = rng.gen_range(0, y_size);
-        let c = {
-            if rng.gen::<f64>() < 0.5 {
-                c0.interpolate(c1, rng.gen::<f64>().powf(2.0))
-            } else {
-                Color::black()
-            }
-        };
+        let c = pick_color(c0, c1, &mut rng);
         frame[y][x] = c;
 
         let mut buf = Vec::with_capacity(x_size * y_size * 3);