Implement delayed output

This just sets the time field on the ALSA packet.  It works!

I had planned to do something much more complicated but if this works
out, everything is easy.

1 files changed, 6 insertions, 1 deletions

diff --git a/midi-dump.hs b/midi-dump.hs
index 146ac5d..90a1bae 100644
--- a/midi-dump.hs
+++ b/midi-dump.hs
@@ -28,6 +28,8 @@ import qualified Sound.ALSA.Sequencer
 import qualified Sound.ALSA.Sequencer.Address
 import qualified Sound.ALSA.Sequencer.Port
 import qualified Sound.ALSA.Sequencer.Queue
+import qualified Sound.ALSA.Sequencer.Time as Time
+import qualified Sound.ALSA.Sequencer.RealTime as RealTime
 
 verbose :: Bool
 verbose = False
@@ -131,11 +133,14 @@ _playNote noteOn note =
   playNoteEv $ Event.NoteEv onoff note
   where onoff = if noteOn then Event.NoteOn else Event.NoteOff
 
+delayEvent :: Event.T -> Integer -> Event.T
+delayEvent evt nanosecs = evt {Event.time = Time.consRel $ Time.Real (RealTime.fromInteger nanosecs)}
+
 playNoteEv :: Event.Data -> RWST LoopEnv () LoopState IO ()
 playNoteEv nevdata = do
   ms <- getMidiSender
   publicAddr <- asks _publicAddr
-  liftIO $ ms $ Event.simple publicAddr nevdata
+  liftIO $ ms $ Event.simple publicAddr nevdata `delayEvent` (10 * 10^(9::Int))
 
 _whenFlag :: forall (m :: * -> *) s. MonadState s m => (s -> Bool) -> m () -> m ()
 _whenFlag flag f = gets flag >>= flip when f