flesh out sequencer

src/event.rs

@@ -6,6 +6,7 @@ pub struct Event {
 
     // Timing
     pub time: Option<f64>,
+    pub delta: Option<f64>,
     pub repeat: Option<f32>,
     pub duration: Option<f32>,
     pub gate: Option<f32>,
@@ -172,6 +173,7 @@ impl Event {
             match key {
                 "doux" | "dirt" => event.cmd = Some(val.to_string()),
                 "time" | "t" => event.time = val.parse().ok(),
+                "delta" => event.delta = val.parse().ok(),
                 "repeat" | "rep" => event.repeat = val.parse().ok(),
                 "duration" | "dur" | "d" => event.duration = val.parse().ok(),
                 "gate" => event.gate = val.parse().ok(),

src/lib.rs

@@ -263,7 +263,11 @@ impl Engine {
         }
     }
 
-    fn play_event(&mut self, event: Event) -> Option<usize> {
+    fn play_event(&mut self, mut event: Event) -> Option<usize> {
+        if let Some(delta) = event.delta {
+            event.time = Some(self.time + delta);
+            event.delta = None;
+        }
         if event.time.is_some() {
             // ALL events with time go to schedule (like dough.c)
             // This ensures repeat works correctly for time=0 events