1 files changed, 32 insertions, 0 deletions
diff --git a/src/synth/triangle.rs b/src/synth/triangle.rs
new file mode 100644
index 0000000..c8380a1
--- /dev/null
+++ b/src/synth/triangle.rs
@@ -0,0 +1,32 @@
+use super::*;
+
+#[derive(Debug)]
+pub struct Triangle {
+    pub freq: GenBox,
+    pub phase: f32,
+    pub buf: SampleBuffer,
+}
+
+impl Generator for Triangle {
+    fn eval<'a>(&'a mut self, params: &Parameters) -> &'a SampleBuffer {
+        self.buf.rate = Rate::Sample;
+
+        let pvel = self.freq.eval(params).first() / params.env.sample_rate;
+        for i in 0..self.buf.len() {
+            let ph = (self.phase + pvel * (i as f32)) % 1.0;
+            self.buf[i] = if ph < 0.25 {
+                4.0 * ph
+            } else if ph > 0.75 {
+                4.0 * ph - 4.0
+            } else {
+                -4.0 * ph + 2.0
+            };
+        }
+
+        self.phase = (self.phase + pvel * (self.buf.len() as f32)) % 1.0;
+        &self.buf
+    }
+    fn set_buffer(&mut self, buf: SampleBuffer) -> SampleBuffer {
+        mem::replace(&mut self.buf, buf)
+    }
+}