duration is beats not repeat

src/seq.rs

@@ -4,12 +4,14 @@ use crate::syn;
 pub struct SynSeq {
    seq: Seq,
    syn: syn::Syn,
+   state: Option<tone::Tone>,
 }
 
 pub fn new_syn(syn: syn::Syn) -> SynSeq {
    SynSeq{
       seq: new(),
       syn: syn,
+      state: None,
    }
 }
 
@@ -19,9 +21,15 @@ impl SynSeq {
    }
 
    pub fn render(&mut self, left: &mut [f32], right: &mut [f32]) {
-      if let Some(tone) = self.seq.pop() {
-         self.syn.set(tone);
-      }
+      let state = self.state.clone();
+      match self.seq.pop() {
+         Some(tone) if (state.is_none() || tone != state.unwrap()) => {
+            self.syn.set(tone.clone());
+            self.state = Some(tone);
+         },
+         None => { self.state = None; },
+         _ => {},
+      };
       self.syn.render(left, right);
    }