marshalling stream formats

[EsounD.git] / Sound / EsounD.hs

diff --git a/Sound/EsounD.hs b/Sound/EsounD.hs
index ba46305e0af46eaaf354d81d9d16931e29d8a467..a088e9072c79e8fbac137a5250c1f1fb769d87ee 100644 (file)
--- a/Sound/EsounD.hs
+++ b/Sound/EsounD.hs
@@ -1,45 +1,75 @@
 -- | Type-safe bindings to EsounD with monadic regions.
 module Sound.EsounD
-    ( Player
+    ( Frame
+
+    , Channels
+    , Mono
+    , Stereo
+
+    , Player
     , openPlayer
     )
     where
 
+import Bindings.EsounD
 import Control.Monad.CatchIO
 import Control.Monad.Trans.Region
+import Data.Bits
+import Data.Int
 import Network
+import Prelude.Unicode
 import System.IO.SaferFileHandles
 
-{-
+class Frame fr where
+    frameFmt ∷ fr → C'esd_format_t
+
+instance Frame Int8 where
+    frameFmt _ = c'ESD_BITS8
+
+instance Frame Int16 where
+    frameFmt _ = c'ESD_BITS16
+
+class Channels ch where
+    channelFmt ∷ ch → C'esd_format_t
+
 data Mono
+instance Channels Mono where
+    channelFmt _ = c'ESD_MONO
+
 data Stereo
+instance Channels Stereo where
+    channelFmt _ = c'ESD_STEREO
 
-data Recorder frame channels
-data Filter   frame channels
-data Sampler
--}
 
 -- ^ An ESD handle for playing a stream.
-data Player frame channels (r ∷ * → *)
+data Player fr ch (r ∷ * → *)
     = Player {
         plRate   ∷ Int
       , plHandle ∷ RegionalFileHandle WriteMode r
       }
 
-instance Dup (Player frame channels) where
+instance Dup (Player fr ch) where
     dup pl
         = do h' ← dup (plHandle pl)
              return pl { plHandle = h' }
 
--- ^ Open an ESD handle for playing a stream.
-openPlayer ∷ MonadCatchIO pr
+-- | Open an ESD handle for playing a stream.
+openPlayer ∷ ∀ fr ch s pr.
+               ( Frame fr
+               , Channels ch
+               , MonadCatchIO pr
+               )
            ⇒ Int          -- ^ sample rate for the stream.
            → HostName     -- ^ host to connect to.
            → Maybe String -- ^ name used to identify this stream to
                            --   ESD (if any).
-           → RegionT s pr (Player frame channels (RegionT s pr))
+           → RegionT s pr (Player fr ch (RegionT s pr))
 openPlayer rate host name
-    = return Player {
-        plRate   = rate
-      , plHandle = error "FIXME: not implemented"
-      }
+    = do let fmt = frameFmt   ((⊥) ∷ fr) .&.
+                   channelFmt ((⊥) ∷ ch) .&.
+                   c'ESD_STREAM            .&.
+                   c'ESD_PLAY
+         return Player {
+                      plRate   = rate
+                    , plHandle = error "FIXME: not implemented"
+                    }