drawing and singing fixes

src/sing/jack_perf.rs

@@ -0,0 +1,22 @@
+use crate::{*, time::PerfModel};
+pub use ::jack::{*, contrib::{*, ClosureProcessHandler}};
+
+pub trait JackPerfModel {
+    fn update_from_jack_scope (&self, t0: Option<u64>, scope: &ProcessScope);
+}
+
+impl JackPerfModel for PerfModel {
+    fn update_from_jack_scope (&self, t0: Option<u64>, scope: &ProcessScope) {
+        if let Some(t0) = t0 {
+            let t1 = self.clock.raw();
+            self.used.store(
+                self.clock.delta_as_nanos(t0, t1) as f64,
+                Relaxed,
+            );
+            self.window.store(
+                scope.cycle_times().unwrap().period_usecs as f64,
+                Relaxed,
+            );
+        }
+    }
+}