1 files changed, 49 insertions, 0 deletions
diff --git a/klangfarbrs/src/partial.rs b/klangfarbrs/src/partial.rs
new file mode 100644
index 0000000..336f005
--- /dev/null
+++ b/klangfarbrs/src/partial.rs
@@ -0,0 +1,49 @@
+use super::{ Amplitude, Hz, Line, Millisecond, Osc, Sample, SamplesPerSecond };
+
+pub struct Partial {
+    amplitude: Amplitude,
+    relative_duration: f32,
+    relative_frequency: f32,
+    detune: Hz,
+    osc: Osc,
+    attack: Line,
+    decay: Line,
+}
+
+impl Partial {
+    pub fn new(
+        amplitude: Amplitude,
+        relative_duration: f32,
+        relative_frequency: f32,
+        detune: Hz,
+        sample_rate: SamplesPerSecond,
+        base_duration: Millisecond,
+        base_frequency: Hz,
+    ) -> Self {
+        let freq = base_frequency * relative_frequency + detune;
+        let decay_duration = base_duration as f32 * relative_duration;
+
+        Self {
+            amplitude, relative_duration, relative_frequency, detune,
+            osc: Osc::new(freq, sample_rate),
+            attack: Line::new(0.0, amplitude, 5, sample_rate),
+            decay: Line::new(amplitude, 0.0, decay_duration as u32, sample_rate),
+        }
+    }
+}
+
+impl Iterator for Partial {
+    type Item = Sample;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        let amplitude = match self.attack.next() {
+            Some(amp) => Some(amp),
+            None => self.decay.next()
+        };
+
+        match amplitude {
+            Some(amp) => Some(self.osc.next().unwrap() * amp),
+            None => None
+        }
+    }
+}