Allow for parameters to be changed by io actions

app/Main.hs

@@ -51,12 +51,14 @@ main = do
         (initializeWorld $ generateFromTree lev1 $ initWorld)
         (-- \((bs:fs:ts:_),tes) w -> --do render setparams w egFade
          \preData w -> --do render setparams w egFade
+                        do
                       renderPicture' preData (_cameraRot w) (_cameraZoom w) 
                                              (_cameraPos w)
                                              (_windowX w,_windowY w) 
                                             (wallsForGloom' w)
                                             (lightsForGloom' w)
                                             (draw blank w)
+                      return preData
                       --renderPicture' preData (_windowX w,_windowY w) (Circle 5)
 --            renderPicture' preData 
 --                          (pictures [scale 0.5 0.9 $ polygon [(0,0),(0,-0.5),(-0.5,-0.5),(-0.5,0.0)]
@@ -65,7 +67,6 @@ main = do
 --                                    ]
 --                          )
         )
-        (\_ _ -> return)       
         (flip $ menuEvents $ flip handleEvent)
         (\w -> Just $ update w)
     Mix.closeAudio

src/Loop.hs

@@ -28,13 +28,12 @@ setupLoop :: String
         -> IO setupParams
         -> (setupParams -> IO ())
         -> world
-        -> (setupParams -> world -> IO ())
-        -> (setupParams -> world -> storableSideEffects -> IO storableSideEffects)
+        -> (setupParams -> world -> IO setupParams)
         -> (world -> Event -> Maybe world)
         -> (world -> Maybe world)
         -> IO ()
 setupLoop wName xSize ySize 
-            customInit initCleanup startWorld sideEffects storableFn eventFn worldFn = do 
+            customInit initCleanup startWorld sideEffects eventFn worldFn = do 
     initializeAll
     bracket (createWindow (T.pack wName) (winConfig xSize ySize)) destroyWindow
         (\window -> 
@@ -48,7 +47,7 @@ setupLoop wName xSize ySize
                             GL.clearColor $= GL.Color4 0 0.5 0 1
                             GL.clearDepth $= (200)
                             doLoop setup window startWorld
-                                   sideEffects storableFn eventFn worldFn
+                                   sideEffects eventFn worldFn
                  )
         )
 
@@ -60,12 +59,11 @@ setupLoop wName xSize ySize
 --            -> IO ()
 doLoop setup window startWorld
         worldSideEffects 
-        storableFn
         eventFn 
         worldUpdate 
   = do
     GL.clear [GL.ColorBuffer,GL.DepthBuffer]
-    worldSideEffects setup startWorld
+    newParams <- worldSideEffects setup startWorld
     glSwapWindow window
     --worldSideEffects setup updatedWorld
     startLoopTicks <- ticks
@@ -83,7 +81,7 @@ doLoop setup window startWorld
             endLoopTicks <- ticks -- it might be better to use System.Clock (monotonic)
             let delay = max 0 (10 + fromIntegral startLoopTicks - fromIntegral endLoopTicks)
             threadDelay (delay * 1000)
-            doLoop setup window updatedWorld worldSideEffects storableFn eventFn worldUpdate
+            doLoop newParams window updatedWorld worldSideEffects eventFn worldUpdate
         Nothing -> return ()
 
 applyEvents :: (world0 -> Event -> Maybe world0)