wip: refactor pt.12, separate tek_snd

crates/tek_snd/src/snd_sequencer.rs

@@ -0,0 +1,37 @@
+use crate::*;
+
+pub struct MIDIPlayerAudio {
+    model: Arc<RwLock<MIDIPlayer>>
+}
+
+impl From<&Arc<RwLock<MIDIPlayer>>> for MIDIPlayerAudio {
+    fn from (model: &Arc<RwLock<MIDIPlayer>>) -> Self {
+        Self { model: model.clone() }
+    }
+}
+
+/// JACK process callback for a sequencer's phrase player/recorder.
+impl Audio for MIDIPlayer {
+    fn process (&mut self, _: &Client, scope: &ProcessScope) -> Control {
+        let has_midi_outputs = self.has_midi_outputs();
+        let has_midi_inputs = self.has_midi_inputs();
+        // Clear output buffer(s)
+        self.clear(scope, false);
+        // Write chunk of phrase to output, handle switchover
+        if self.play(scope) {
+            self.switchover(scope);
+        }
+        if has_midi_inputs {
+            if self.recording || self.monitoring {
+                // Record and/or monitor input
+                self.record(scope)
+            } else if has_midi_outputs && self.monitoring {
+                // Monitor input to output
+                self.monitor(scope)
+            }
+        }
+        // Write to output port(s)
+        self.write(scope);
+        Control::Continue
+    }
+}