Monitor

[EsounD.git] / Sound / EsounD / Internals.hs

diff --git a/Sound/EsounD/Internals.hs b/Sound/EsounD/Internals.hs
index 8d28ed8e346bf2aefcaf54d4459e6ef085f7da9c..fcaff1e5e88d84d5c887bf0a45e3d34f93b1e865 100644 (file)
--- a/Sound/EsounD/Internals.hs
+++ b/Sound/EsounD/Internals.hs
@@ -11,6 +11,7 @@ module Sound.EsounD.Internals
     , Mono
     , Stereo
     , interleave
+    , deinterleave
 
     , wrapSocket
     , closeSocket
@@ -53,7 +54,7 @@ instance Channels Stereo where
     channelFmt _ = c'ESD_STEREO
 
 {-# INLINE interleave #-}
-interleave ∷ Frame fr ⇒ L.Vector fr → L.Vector fr → L.Vector fr
+interleave ∷ Storable α ⇒ L.Vector α → L.Vector α → L.Vector α
 interleave l r
     -- THINKME: consider using storablevector-streamfusion
     = let Just (lFr, l') = L.viewL l
@@ -62,6 +63,21 @@ interleave l r
       in
         L.cons lFr (L.cons rFr lr')
 
+{-# INLINE deinterleave #-}
+deinterleave ∷ Storable α ⇒ L.Vector α → (L.Vector α, L.Vector α)
+deinterleave v
+    -- THINKME: consider using storablevector-streamfusion
+    = let (lr, v') = L.splitAt 2 v
+      in
+        if L.null lr then
+            (L.empty, L.empty)
+        else
+            let Just (lFr, r) = L.viewL lr
+                Just (rFr, _) = L.viewL r
+                (l', r') = deinterleave v'
+            in
+              (L.cons lFr l', L.cons rFr r')
+
 -- Utility functions
 wrapSocket ∷ String → CInt → IO Handle
 wrapSocket e (-1) = fail e