Add some helper functions

Author: gridbugs

core/src/lib.rs

@@ -46,3 +46,15 @@ where
         self.as_ref().with_channel(|channel, s| s.set(f(channel)));
     }
 }
+
+impl Stereo<SV<f32>, SV<f32>> {
+    pub fn with_volume<V>(self, volume: V) -> Self
+    where
+        V: SigT<Item = f32> + Sync + Send + 'static,
+    {
+        let out = StereoPair::new_fn(|| sv(0.));
+        let volume = sig_shared(volume);
+        self.set_channel(|channel| out.get(channel).clone() * volume.clone());
+        out
+    }
+}

core/src/stereo.rs

@@ -1,4 +1,4 @@
-use crate::{Buf, SigCtx, SigSampleIntoBufT, SigT};
+use crate::{Buf, Sig, SigCtx, SigSampleIntoBufT, SigT, sig_ops::sig_add};
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub enum Channel {
@@ -114,6 +114,16 @@ where
     }
 }
 
+impl<L, R> Stereo<L, R>
+where
+    L: SigT<Item = f32>,
+    R: SigT<Item = f32>,
+{
+    pub fn sum(self) -> Sig<sig_add::OpSigSig<L, R>> {
+        Sig(self.left) + Sig(self.right)
+    }
+}
+
 impl<L, R> Stereo<L, R>
 where
     L: SigSampleIntoBufT,