Add ability to split rainbow

src/pattern/moving_rainbow.rs

@@ -12,6 +12,7 @@ pub struct MovingRainbowParams {
     pub width: u8,
     pub forward: bool,
     pub skip: u8,
+    pub fromcenter: bool,
 }
 
 impl Default for MovingRainbowParams {
@@ -20,6 +21,7 @@ impl Default for MovingRainbowParams {
             width: 8,
             forward: true,
             skip: 4,
+            fromcenter: false,
         }
     }
 }
@@ -30,6 +32,7 @@ impl FormRender for MovingRainbowParams {
             self.width.render("width", None),
             self.forward.render("forward", None),
             self.skip.render("skip", None),
+            self.fromcenter.render("fromcenter", None),
         ]
         .concat()
     }
@@ -38,9 +41,12 @@ impl FormRender for MovingRainbowParams {
 #[derive(Clone, Debug)]
 pub struct MovingRainbow {
     lights_buf: VecDeque<Rgb>,
+    /// The index to split, if moving from the inside out
+    split_index: usize,
     skip: u8,
     width: u8,
     forward: bool,
+    fromcenter: bool,
 }
 impl Default for MovingRainbow {
     fn default() -> Self {
@@ -54,6 +60,8 @@ impl MovingRainbow {
             skip: params.skip,
             width: params.width,
             forward: params.forward,
+            fromcenter: params.fromcenter,
+            split_index: 0,
         }
     }
 }
@@ -83,6 +91,8 @@ impl Pattern for MovingRainbow {
         // Always a factor of length_factor
         let buf_length = color::min_with_factor(num_lights, length_factor)?;
 
+        self.split_index = (num_lights / 2_u16) as usize;
+
         self.lights_buf = RAINBOW
             .iter()
             .flat_map(|&x| {
@@ -96,7 +106,13 @@ impl Pattern for MovingRainbow {
 
         Ok(())
     }
-    fn get_strip(&self) -> vec_deque::Iter<Rgb> {
-        self.lights_buf.iter()
+    fn get_strip<'a>(&'a self) -> ColorIterator {
+        if self.fromcenter {
+            let tmp_iter = self.lights_buf.iter().take(self.split_index);
+            let tmp_iter2 = self.lights_buf.iter().take(self.split_index).rev();
+            Box::new(tmp_iter.chain(tmp_iter2))
+        } else {
+            Box::new(self.lights_buf.iter())
+        }
     }
 }