1 files changed, 60 insertions, 0 deletions
diff --git a/src/synth/util.rs b/src/synth/util.rs
new file mode 100644
index 0000000..5bde721
--- /dev/null
+++ b/src/synth/util.rs
@@ -0,0 +1,60 @@
+use super::*;
+
+#[derive(Debug)]
+pub struct ControlRate {
+    pub value: GenBox,
+    pub buf: SampleBuffer,
+}
+
+impl ControlRate {
+    pub fn new(mut gen: GenBox) -> ControlRate {
+        gen.set_buffer(SampleBuffer::new(1));
+        ControlRate { value: gen, buf: SampleBuffer::new(1) }
+    }
+}
+
+impl Generator for ControlRate {
+    fn eval<'a>(&'a mut self, params: &Parameters) -> &'a SampleBuffer {
+        self.buf.rate = Rate::Control;
+        self.buf.update_from(self.value.eval(params));
+        &self.buf
+    }
+    fn buffer(&self) -> &SampleBuffer { &self.buf }
+    fn set_buffer(&mut self, buf: SampleBuffer) -> SampleBuffer { mem::replace(&mut self.buf, buf) }
+}
+
+pub struct ControlRateFactory;
+
+impl GeneratorFactory for ControlRateFactory {
+    fn new(&self, params: &mut FactoryParameters) -> Result<GenBox, GenFactoryError> {
+        Ok(Box::new(ControlRate::new(params.remove_param("gen", 0)?.into_gen()?)))
+    }
+}
+
+pub static FactoryControlRate: ControlRateFactory = ControlRateFactory;
+
+#[derive(Debug)]
+pub struct SampleRate {
+    pub buf: SampleBuffer,
+}
+
+impl Generator for SampleRate {
+    fn eval<'a>(&'a mut self, params: &Parameters) -> &'a SampleBuffer {
+        self.buf.set(params.env.sample_rate);
+        &self.buf
+    }
+    fn buffer(&self) -> &SampleBuffer { &self.buf }
+    fn set_buffer(&mut self, buf: SampleBuffer) -> SampleBuffer {
+        mem::replace(&mut self.buf, buf)
+    }
+}
+
+pub struct SampleRateFactory;
+
+impl GeneratorFactory for SampleRateFactory {
+    fn new(&self, params: &mut FactoryParameters) -> Result<GenBox, GenFactoryError> {
+        Ok(Box::new(SampleRate { buf: SampleBuffer::new(1) }))
+    }
+}
+
+pub static FactorySampleRate: SampleRateFactory = SampleRateFactory;