Smoothing out discontinuities

1 files changed, 12 insertions, 1 deletions

diff --git a/trivmix/Trivmix.hs b/trivmix/Trivmix.hs
index fe62619..2cd1252 100644
--- a/trivmix/Trivmix.hs
+++ b/trivmix/Trivmix.hs
@@ -113,6 +113,17 @@ main = execParser opts >>= trivmix
 trivmix :: Options -> IO ()
 trivmix Options{..} = do
   level <- newMVar initialLevel
+  level' <- newMVar initialLevel
+  forkIO $ forever $ do -- Smooth out discontinuity
+    let
+      fps = 200
+      interval = 0.2
+      frames = interval * fps
+      delay = round $ recip fps * 10e6
+      linInt x a b = a * (1 - x) + b * x
+    newLevel <- readMVar level
+    currentLevel <- readMVar level'
+    mapM_ (\x -> swapMVar level' (asFloat (linInt x) currentLevel newLevel) >> threadDelay delay) ([0..frames] :: [Float])
   let withFiles = foldl (.) id $ map (\f -> onStateFile f (show initialLevel ++ "\n")) levelFiles
   withFiles $ withINotify $ \inotify -> do
     handleFiles inotify level levelFiles
@@ -126,7 +137,7 @@ trivmix Options{..} = do
             Just run' -> do
               (_, _, _, ph) <- createProcess $ (proc run' [client ++ ":" ++ input, client ++ ":" ++ output]) { delegate_ctlc = True }
               return ()
-        Audio.withProcessMono client' input' (mix level) output' $
+        Audio.withProcessMono client' input' (mix level') output' $
           Jack.withActivation client' $ Trans.lift Jack.waitForBreak
 
 mix :: MVar Level -> CFloat -> IO CFloat