Extend cnoise to multiple palettes, add new default palette for 37C3

src/bin/cnoise/main.rs

@@ -5,6 +5,7 @@ use std::iter::repeat_with;
 use std::thread::sleep;
 use std::time::Duration;
 
+use rand::seq::SliceRandom;
 use rand::thread_rng;
 use rand::Rng;
 
@@ -21,35 +22,56 @@ 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()
+#[derive(Clone, Debug)]
+struct Palette(Vec<(Color, Color)>);
+impl Palette {
+    fn pick<R>(&self, rng: &mut R, p: f64) -> Color
+    where
+        R: Rng,
+    {
+        let &(c0, c1) = self.0.choose(rng).unwrap();
+
+        if rng.gen::<f64>() < p {
+            c0.interpolate(c1, rng.gen::<f64>().powf(2.0))
+        } else {
+            Color::black()
+        }
     }
 }
 
+const DEFAULT_ARG: usize = 37;
+
 fn main() -> std::io::Result<()> {
     let args = args().collect::<Vec<_>>();
     eprintln!("executing {}", args[0]);
 
     let x_size = args[1].parse::<usize>().unwrap();
     let y_size = args[2].parse::<usize>().unwrap();
-    eprintln!("screen size {}x{}", x_size, y_size);
+    let arg = args[3].parse::<usize>().unwrap_or(DEFAULT_ARG);
+    eprintln!("screen size {}x{}, arg {}", x_size, y_size, arg);
 
     let t_frame = 0.040; // s
     let delay = Duration::new(0, (1_000_000_000.0 * t_frame) as u32);
 
-    let c0 = Color::new(0, 138, 170);
-    let c1 = Color::new(0, 160, 95);
-
     let mut rng = thread_rng();
 
+    let palette_35 = Palette(vec![(Color::new(0, 138, 170), Color::new(0, 160, 95))]);
+    let palette_37 = Palette(vec![
+        (Color::new(153, 0, 0), Color::new(255, 0, 0)),
+        (Color::new(0, 153, 0), Color::new(0, 255, 0)),
+        (Color::new(0, 0, 153), Color::new(0, 0, 255)),
+        (Color::new(153, 153, 0), Color::new(255, 255, 0)),
+        (Color::new(0, 153, 153), Color::new(0, 255, 255)),
+        (Color::new(153, 0, 153), Color::new(255, 0, 255)),
+    ]);
+
+    let palette = match arg {
+        35 => palette_35,
+        _ => palette_37,
+    };
+
     let mut frame = repeat_with(|| {
-        repeat_with(|| pick_color(c0, c1, &mut rng))
+        repeat_with(|| palette.pick(&mut rng, 0.5))
             .take(x_size)
             .collect::<Vec<_>>()
     })
@@ -58,7 +80,7 @@ fn main() -> std::io::Result<()> {
     loop {
         let x = rng.gen_range(0..x_size);
         let y = rng.gen_range(0..y_size);
-        let c = pick_color(c0, c1, &mut rng);
+        let c = palette.pick(&mut rng, 0.5);
         frame[y][x] = c;
 
         let mut buf = Vec::with_capacity(x_size * y_size * 3);