more reorg; newtype Binds and Views

src/sample_voice.rs

@@ -0,0 +1,30 @@
+use crate::*;
+
+/// A currently playing instance of a sample.
+#[derive(Default, Debug, Clone)] pub struct Voice {
+    pub sample:   Arc<RwLock<Sample>>,
+    pub after:    usize,
+    pub position: usize,
+    pub velocity: f32,
+}
+
+impl Iterator for Voice {
+    type Item = [f32;2];
+    fn next (&mut self) -> Option<Self::Item> {
+        if self.after > 0 {
+            self.after -= 1;
+            return Some([0.0, 0.0])
+        }
+        let sample = self.sample.try_read().unwrap();
+        if self.position < sample.end {
+            let position = self.position;
+            self.position += 1;
+            return sample.channels[0].get(position).map(|_amplitude|[
+                sample.channels[0][position] * self.velocity * sample.gain,
+                sample.channels[0][position] * self.velocity * sample.gain,
+            ])
+        }
+        None
+    }
+}
+