fix(rainbow): name variables

src/main.rs

@@ -143,9 +143,17 @@ fn rainbow(layout: Layout, frame: u32) -> RgbImage {
     let w = layout.width_px();
     let h = layout.height_px();
 
+    let tightness = 100.0;
+    let slowness = 200;
+    let brightness = 0.1;
+
     RgbImage::from_fn(w, h, |x, y| {
-        let RGB { r, g, b } =
-            HSV::from_f32((x + y + frame % 100) as f32 / 100.0 % 1.0, 1.0, 0.1).to_rgb();
+        let RGB { r, g, b } = HSV::from_f32(
+            (x + y) as f32 / tightness % 1.0 + (frame % slowness) as f32 / slowness as f32,
+            1.0,
+            brightness,
+        )
+        .to_rgb();
         Rgb([(r * 255.0) as u8, (g * 255.0) as u8, (b * 255.0) as u8])
     })
 }