wip: refactor pt.12, separate tek_snd

crates/tek_snd/src/snd_arrange.rs

@@ -0,0 +1,22 @@
+use crate::*;
+
+pub struct ArrangementAudio {
+    model: Arc<RwLock<Arrangement>>
+}
+
+impl From<&Arc<RwLock<Arrangement>>> for ArrangementAudio {
+    fn from (model: &Arc<RwLock<Arrangement>>) -> Self {
+        Self { model: model.clone() }
+    }
+}
+
+impl Audio for ArrangementAudio {
+    #[inline] fn process (&mut self, client: &Client, scope: &ProcessScope) -> Control {
+        for track in self.model.write().unwrap().tracks.iter_mut() {
+            if track.player.process(client, scope) == Control::Quit {
+                return Control::Quit
+            }
+        }
+        Control::Continue
+    }
+}