diff --git a/gridland.cabal b/gridland.cabal
--- a/gridland.cabal
+++ b/gridland.cabal
@@ -1,5 +1,5 @@
 name:                gridland
-version:             0.1.0.2
+version:             0.1.0.3
 synopsis:            Grid-based multimedia engine
 description:         Learn Haskell by drawing sprites and playing music and sound effects.
 license:             MIT
@@ -26,7 +26,10 @@
   other-modules:
     GridLand.Import
     GridLand.Data
-  -- other-extensions:
+    GridLand.SDL
+    GridLand.Color
+  other-extensions:
+    CPP
   default-extensions:
     RecordWildCards
     LambdaCase
@@ -52,6 +55,10 @@
     safe
   hs-source-dirs: src
   default-language: Haskell2010
+  if arch(i386)
+    cpp-options: -DARCH_32
+  if arch(x86_64)
+    cpp-options: -DARCH_64
 
 executable demo
   main-is: Main.hs
diff --git a/src/GridLand.hs b/src/GridLand.hs
--- a/src/GridLand.hs
+++ b/src/GridLand.hs
@@ -42,43 +42,34 @@
     , getMousePosition
     ) where
 
--- base
-import Debug.Trace
-import Data.IORef
-import Data.Char
-import Data.Maybe
-import Control.Arrow
-import System.Environment
--- SDL
 import qualified Graphics.UI.SDL as SDL
 import qualified Graphics.UI.SDL.Video as SDL
--- SDL-image
 import qualified Graphics.UI.SDL.Image as Image
--- SDL-ttf (unused)
 -- import qualified Graphics.UI.SDL.TTF as TTF
--- SDL-mixer
 import qualified Graphics.UI.SDL.Mixer as Mixer
--- SDL-gfx
 import qualified Graphics.UI.SDL.Framerate as Gfx
 import qualified Graphics.UI.SDL.Primitives as Gfx
 import qualified Graphics.UI.SDL.Rotozoomer as Gfx
--- containers
 import qualified Data.Map as Map
 import qualified Data.Set as Set
--- grid
 import qualified Math.Geometry.Grid as Grid
--- vector
 import qualified Data.Vector as V
--- mtl
 import qualified Control.Monad.State as State
 import qualified Control.Monad.RWS as RWS
--- array
 import qualified Data.Array as Array
--- safe
 import qualified Safe as Safe
 
+import Debug.Trace
+import Data.IORef
+import Data.Char
+import Data.Maybe
+import Control.Arrow
+import System.Environment
+
 import GridLand.Import
 import GridLand.Data
+import GridLand.SDL
+import GridLand.Color
 
 newTodo :: Todo
 newTodo = Todo Map.empty Map.empty Map.empty (BkdColor White)
@@ -101,19 +92,6 @@
     noFilters = [(NoFilter, theta) | theta <- spriteDegrees]
     filters = [(cf c, theta) | cf <- [Tint, Replace], c <- [minBound..maxBound], theta <-  spriteDegrees]
 
-setColorKey :: (Word8, Word8, Word8) -> SDL.Surface -> IO SDL.Surface
-setColorKey (r, g, b) sur = mapRGB sur r g b >>= SDL.setColorKey sur [SDL.SrcColorKey] >> return sur
-
-mapRGB :: SDL.Surface -> Word8 -> Word8 -> Word8 -> IO SDL.Pixel
-mapRGB = SDL.mapRGB . SDL.surfaceGetPixelFormat
-
-colorToPixel :: Color -> SDL.Pixel
-colorToPixel color = let
-    (r',g,b') = colorValue color
-    (r,b) = (b',r')
-    v = shiftL 0xff (8 * 3)  .|. shiftL (fromIntegral b) (8 * 2) .|. shiftL (fromIntegral g) (8 * 1) .|. (fromIntegral r)
-    in SDL.Pixel v
-
 loadSpriteStretch :: FilePath -> Stretch -> GridLand a Sprite
 loadSpriteStretch rawPath stretch = do
     path <- correctPath rawPath
@@ -158,16 +136,16 @@
 mapFilterColor ABGR = filterColorABGR
 
 filterColorABGR :: ColorFilter -> Word32 -> SDL.Pixel
-filterColorABGR = mkFilterColor toColorABGR32 fromColorABGR32 0xff000000
+filterColorABGR = mkFilterColor toColorABGR fromColorABGR 0xff000000
 
 filterColorARGB :: ColorFilter -> Word32 -> SDL.Pixel
-filterColorARGB = mkFilterColor toColorARGB32 fromColorARGB32 0xff000000
+filterColorARGB = mkFilterColor toColorARGB fromColorARGB 0xff000000
 
 filterColorRGBA :: ColorFilter -> Word32 -> SDL.Pixel
-filterColorRGBA = mkFilterColor toColorRGBA32 fromColorRGBA32 0x000000ff
+filterColorRGBA = mkFilterColor toColorRGBA fromColorRGBA 0x000000ff
 
 filterColorBGRA :: ColorFilter -> Word32 -> SDL.Pixel
-filterColorBGRA = mkFilterColor toColorBGRA32 fromColorBGRA32 0x000000ff
+filterColorBGRA = mkFilterColor toColorBGRA fromColorBGRA 0x000000ff
 
 mkFilterColor
     :: (Word8 -> Word8 -> Word8 -> Word32)
@@ -209,20 +187,6 @@
         else p
 
 -- This is a necessary hack because the SDL bindings are insufficient
-surfacePixelFormat :: SDL.Surface -> IO PixelFormat
-surfacePixelFormat sur = do
-    let fmt = SDL.surfaceGetPixelFormat sur
-    rShift <- pixelFormatGetRShift fmt
-    bShift <- pixelFormatGetBShift fmt
-    gShift <- pixelFormatGetGShift fmt
-    aShift <- pixelFormatGetAShift fmt
-    return $ case (rShift, gShift, bShift, aShift) of
-        ( 0,  8, 16, 24) -> ABGR
-        (16,  8,  0, 24) -> ARGB
-        (24, 16,  8,  0) -> RGBA
-        ( 8, 16, 24,  0) -> BGRA
-        _ -> ABGR -- default
-
 correctPath :: FilePath -> GridLand a FilePath
 correctPath "" = RWS.gets (pathPrefix . fst)
 correctPath path =
@@ -235,63 +199,6 @@
 loadSprite :: FilePath -> GridLand a Sprite
 loadSprite path = loadSpriteStretch path Pixelated
 
-copySurface :: SDL.Surface -> IO SDL.Surface
-copySurface sur = do
-    copy <- copyFromSurface sur
-    SDL.blitSurface sur Nothing copy Nothing
-    return copy
-
-copyFromSurface :: SDL.Surface -> IO SDL.Surface
-copyFromSurface sur = do
-    let fmt = SDL.surfaceGetPixelFormat sur
-    bpp <- fromIntegral `liftM` SDL.pixelFormatGetBitsPerPixel fmt
-    rMask <- pixelFormatGetRMask fmt
-    gMask <- pixelFormatGetGMask fmt
-    bMask <- pixelFormatGetBMask fmt
-    flags <- SDL.surfaceGetFlags sur
-    aMask <- if elem SDL.SrcColorKey flags then return 0 else pixelFormatGetAMask fmt
-    SDL.createRGBSurface [SDL.SWSurface] (SDL.surfaceGetWidth sur) (SDL.surfaceGetHeight sur) bpp rMask gMask bMask aMask
-
-pixelFormatGetBytes :: Storable a => Int -> SDL.PixelFormat -> IO a
-pixelFormatGetBytes offset fmt = withForeignPtr fmt (\ptr -> peekByteOff ptr offset)
-
-pixelFormatGetRShift, pixelFormatGetGShift, pixelFormatGetBShift, pixelFormatGetAShift :: SDL.PixelFormat -> IO Word8
--- 64 bit
-pixelFormatGetRShift = pixelFormatGetBytes 14
-pixelFormatGetGShift = pixelFormatGetBytes 15
-pixelFormatGetBShift = pixelFormatGetBytes 16
-pixelFormatGetAShift = pixelFormatGetBytes 17
-{- 32 bit
-pixelFormatGetRShift = pixelFormatGetBytes 10
-pixelFormatGetGShift = pixelFormatGetBytes 11
-pixelFormatGetBShift = pixelFormatGetBytes 12
-pixelFormatGetAShift = pixelFormatGetBytes 13
--}
-
-pixelFormatGetRMask, pixelFormatGetGMask, pixelFormatGetBMask, pixelFormatGetAMask :: SDL.PixelFormat -> IO Word32
--- 64 bit
-pixelFormatGetRMask = pixelFormatGetBytes 20
-pixelFormatGetGMask = pixelFormatGetBytes 24
-pixelFormatGetBMask = pixelFormatGetBytes 28
-pixelFormatGetAMask = pixelFormatGetBytes 32
-{- 32 bit
-pixelFormatGetRMask = pixelFormatGetBytes 16
-pixelFormatGetGMask = pixelFormatGetBytes 20
-pixelFormatGetBMask = pixelFormatGetBytes 24
-pixelFormatGetAMask = pixelFormatGetBytes 28
--}
-
-
-getPixel32 :: Int -> Int -> SDL.Surface -> IO SDL.Pixel
-getPixel32 x y s = do
-    pixels <- castPtr `liftM` SDL.surfaceGetPixels s
-    SDL.Pixel `liftM` peekElemOff pixels ((y * SDL.surfaceGetWidth s) + x)
-
-putPixel32 :: Int -> Int -> SDL.Pixel -> SDL.Surface -> IO ()
-putPixel32 x y (SDL.Pixel pixel) s = do
-    pixels <- castPtr `liftM` SDL.surfaceGetPixels s
-    pokeElemOff pixels ((y * SDL.surfaceGetWidth s) + x) pixel
-
 loadBackdropImageStretch :: FilePath -> Stretch -> GridLand a Backdrop
 loadBackdropImageStretch rawPath stretch = do
     path <- correctPath rawPath
@@ -409,74 +316,6 @@
 released :: Key -> Input
 released = flip Key Released
 
-fromColorARGB32 :: Word32 -> (Word8, Word8, Word8)
-fromColorARGB32 c =
-    (fromIntegral ((shiftR c (2 * 8)) .&. 0xff),
-     fromIntegral ((shiftR c 8) .&. 0xff),
-     fromIntegral (c .&. 0xff))
-
-fromColorABGR32 :: Word32 -> (Word8, Word8, Word8)
-fromColorABGR32 c =
-    (fromIntegral (c .&. 0xff),
-     fromIntegral ((shiftR c 8) .&. 0xff),
-     fromIntegral ((shiftR c (2 * 8)) .&. 0xff))
-
-fromColorRGBA32 :: Word32 -> (Word8, Word8, Word8)
-fromColorRGBA32 c =
-    (fromIntegral ((shiftR c (3 * 8)) .&. 0xff),
-     fromIntegral ((shiftR c (2 * 8)) .&. 0xff),
-     fromIntegral ((shiftR c 8) .&. 0xff))
-
-fromColorBGRA32 :: Word32 -> (Word8, Word8, Word8)
-fromColorBGRA32 c =
-    (fromIntegral ((shiftR c 8) .&. 0xff),
-     fromIntegral ((shiftR c (2 * 8)) .&. 0xff),
-     fromIntegral ((shiftR c (3 * 8)) .&. 0xff))
-
-toColorABGR32 :: Word8 -> Word8 -> Word8 -> Word32
-toColorABGR32 r g b =
-    shiftL 0xff (3 * 8) .|.
-    shiftL (fromIntegral b) (2 * 8) .|.
-    shiftL (fromIntegral g) 8 .|.
-    (fromIntegral r)
-
-toColorARGB32 :: Word8 -> Word8 -> Word8 -> Word32
-toColorARGB32 r g b =
-    shiftL 0xff (3 * 8) .|.
-    shiftL (fromIntegral r) (2 * 8) .|.
-    shiftL (fromIntegral g) 8 .|.
-    (fromIntegral b)
-
-toColorBGRA32 :: Word8 -> Word8 -> Word8 -> Word32
-toColorBGRA32 r g b =
-    shiftL (fromIntegral b) (3 * 8) .|.
-    shiftL (fromIntegral g) (2 * 8) .|.
-    shiftL (fromIntegral r) 8 .|.
-    0xff
-
-toColorRGBA32 :: Word8 -> Word8 -> Word8 -> Word32
-toColorRGBA32 r g b =
-    shiftL (fromIntegral r) (3 * 8) .|.
-    shiftL (fromIntegral g) (2 * 8) .|.
-    shiftL (fromIntegral b) 8 .|.
-    0xff
-
-colorValue :: Integral a => Color -> (a, a, a)
-colorValue = \case
-  Red -> (0xcc, 0x00, 0x00)
-  Orange -> (0xff, 0xa5, 0x00)
-  Yellow -> (0xff, 0xff, 0x00)
-  YellowGreen -> (0x7f, 0xff, 0x00)
-  Green -> (0x00, 0x66, 0x00)
-  LightBlue -> (0x66, 0xff, 0xff)
-  Blue -> (0x00, 0x00, 0x99)
-  Pink -> (0xff, 0x66, 0x99)
-  Black -> (0x00, 0x00, 0x00)
-  White -> (0xff, 0xff, 0xff)
-
-colorValue' :: Integral a => Color -> (a -> a -> a -> b) -> b
-colorValue' c f = uncurryN f (colorValue c)
-
 rotations, colors, withoutColors, withColors, totalFrames, colorAngleInterval:: Int
 rotations = 36
 colors = 1 + fromEnum (maxBound :: Color)
@@ -657,7 +496,7 @@
 getColorMap :: SDL.Surface -> IO (Color -> SDL.Pixel)
 getColorMap s = do
     let fmt = SDL.surfaceGetPixelFormat s
-    pixels <- forM [minBound..maxBound] $ \c -> liftIO $ colorValue' c (SDL.mapRGB fmt)
+    pixels <- forM [minBound..maxBound] (\c -> liftIO $ colorValueCurry c (SDL.mapRGB fmt))
     let table = V.fromList pixels
     return $ \c -> table V.! (fromEnum c)
 
diff --git a/src/GridLand/Color.hs b/src/GridLand/Color.hs
new file mode 100644
--- /dev/null
+++ b/src/GridLand/Color.hs
@@ -0,0 +1,80 @@
+module GridLand.Color where
+
+import qualified Graphics.UI.SDL as SDL
+import GridLand.Import
+import GridLand.Data
+import GridLand.SDL
+
+colorToPixel :: Color -> SDL.Pixel
+colorToPixel color = let
+    (r',g,b') = colorValue color
+    (r,b) = (b',r')
+    v = shiftL 0xff (8 * 3)  .|. shiftL (fromIntegral b) (8 * 2) .|. shiftL (fromIntegral g) (8 * 1) .|. (fromIntegral r)
+    in SDL.Pixel v
+
+fromColorARGB :: Word32 -> (Word8, Word8, Word8)
+fromColorARGB c =
+    (fromIntegral ((shiftR c (2 * 8)) .&. 0xff),
+     fromIntegral ((shiftR c 8) .&. 0xff),
+     fromIntegral (c .&. 0xff))
+
+fromColorABGR :: Word32 -> (Word8, Word8, Word8)
+fromColorABGR c =
+    (fromIntegral (c .&. 0xff),
+     fromIntegral ((shiftR c 8) .&. 0xff),
+     fromIntegral ((shiftR c (2 * 8)) .&. 0xff))
+
+fromColorRGBA :: Word32 -> (Word8, Word8, Word8)
+fromColorRGBA c =
+    (fromIntegral ((shiftR c (3 * 8)) .&. 0xff),
+     fromIntegral ((shiftR c (2 * 8)) .&. 0xff),
+     fromIntegral ((shiftR c 8) .&. 0xff))
+
+fromColorBGRA :: Word32 -> (Word8, Word8, Word8)
+fromColorBGRA c =
+    (fromIntegral ((shiftR c 8) .&. 0xff),
+     fromIntegral ((shiftR c (2 * 8)) .&. 0xff),
+     fromIntegral ((shiftR c (3 * 8)) .&. 0xff))
+
+toColorABGR :: Word8 -> Word8 -> Word8 -> Word32
+toColorABGR r g b =
+    shiftL 0xff (3 * 8) .|.
+    shiftL (fromIntegral b) (2 * 8) .|.
+    shiftL (fromIntegral g) 8 .|.
+    (fromIntegral r)
+
+toColorARGB :: Word8 -> Word8 -> Word8 -> Word32
+toColorARGB r g b =
+    shiftL 0xff (3 * 8) .|.
+    shiftL (fromIntegral r) (2 * 8) .|.
+    shiftL (fromIntegral g) 8 .|.
+    (fromIntegral b)
+
+toColorBGRA :: Word8 -> Word8 -> Word8 -> Word32
+toColorBGRA r g b =
+    shiftL (fromIntegral b) (3 * 8) .|.
+    shiftL (fromIntegral g) (2 * 8) .|.
+    shiftL (fromIntegral r) 8 .|.
+    0xff
+
+toColorRGBA :: Word8 -> Word8 -> Word8 -> Word32
+toColorRGBA r g b =
+    shiftL (fromIntegral r) (3 * 8) .|.
+    shiftL (fromIntegral g) (2 * 8) .|.
+    shiftL (fromIntegral b) 8 .|.
+    0xff
+
+colorValue :: Integral a => Color -> (a, a, a)
+colorValue Red = (0xcc, 0x00, 0x00)
+colorValue Orange = (0xff, 0xa5, 0x00)
+colorValue Yellow = (0xff, 0xff, 0x00)
+colorValue YellowGreen = (0x7f, 0xff, 0x00)
+colorValue Green = (0x00, 0x66, 0x00)
+colorValue LightBlue = (0x66, 0xff, 0xff)
+colorValue Blue = (0x00, 0x00, 0x99)
+colorValue Pink = (0xff, 0x66, 0x99)
+colorValue Black = (0x00, 0x00, 0x00)
+colorValue White = (0xff, 0xff, 0xff)
+
+colorValueCurry :: Integral a => Color -> (a -> a -> a -> b) -> b
+colorValueCurry c f = uncurryN f (colorValue c)
diff --git a/src/GridLand/SDL.hs b/src/GridLand/SDL.hs
new file mode 100644
--- /dev/null
+++ b/src/GridLand/SDL.hs
@@ -0,0 +1,85 @@
+{-# LANGUAGE CPP #-}
+
+module GridLand.SDL where
+
+import qualified Graphics.UI.SDL as SDL
+import GridLand.Import
+import GridLand.Data
+
+setColorKey :: (Word8, Word8, Word8) -> SDL.Surface -> IO SDL.Surface
+setColorKey (r, g, b) sur = mapRGB sur r g b >>= SDL.setColorKey sur [SDL.SrcColorKey] >> return sur
+
+mapRGB :: SDL.Surface -> Word8 -> Word8 -> Word8 -> IO SDL.Pixel
+mapRGB = SDL.mapRGB . SDL.surfaceGetPixelFormat
+
+surfacePixelFormat :: SDL.Surface -> IO PixelFormat
+surfacePixelFormat sur = do
+    let fmt = SDL.surfaceGetPixelFormat sur
+    rShift <- pixelFormatGetRShift fmt
+    bShift <- pixelFormatGetBShift fmt
+    gShift <- pixelFormatGetGShift fmt
+    aShift <- pixelFormatGetAShift fmt
+    return $ case (rShift, gShift, bShift, aShift) of
+        ( 0,  8, 16, 24) -> ABGR
+        (16,  8,  0, 24) -> ARGB
+        (24, 16,  8,  0) -> RGBA
+        ( 8, 16, 24,  0) -> BGRA
+        _ -> ABGR -- default
+
+copySurface :: SDL.Surface -> IO SDL.Surface
+copySurface sur = do
+    copy <- copyFromSurface sur
+    SDL.blitSurface sur Nothing copy Nothing
+    return copy
+
+copyFromSurface :: SDL.Surface -> IO SDL.Surface
+copyFromSurface sur = do
+    let fmt = SDL.surfaceGetPixelFormat sur
+    bpp <- fromIntegral `liftM` SDL.pixelFormatGetBitsPerPixel fmt
+    rMask <- pixelFormatGetRMask fmt
+    gMask <- pixelFormatGetGMask fmt
+    bMask <- pixelFormatGetBMask fmt
+    flags <- SDL.surfaceGetFlags sur
+    aMask <- if elem SDL.SrcColorKey flags then return 0 else pixelFormatGetAMask fmt
+    SDL.createRGBSurface [SDL.SWSurface] (SDL.surfaceGetWidth sur) (SDL.surfaceGetHeight sur) bpp rMask gMask bMask aMask
+
+pixelFormatGetBytes :: Storable a => Int -> SDL.PixelFormat -> IO a
+pixelFormatGetBytes offset fmt = withForeignPtr fmt (\ptr -> peekByteOff ptr offset)
+
+pixelFormatGetRShift, pixelFormatGetGShift, pixelFormatGetBShift, pixelFormatGetAShift :: SDL.PixelFormat -> IO Word8
+#ifdef ARCH_64
+pixelFormatGetRShift = pixelFormatGetBytes 14
+pixelFormatGetGShift = pixelFormatGetBytes 15
+pixelFormatGetBShift = pixelFormatGetBytes 16
+pixelFormatGetAShift = pixelFormatGetBytes 17
+#endif
+#ifdef ARCH_32
+pixelFormatGetRShift = pixelFormatGetBytes 10
+pixelFormatGetGShift = pixelFormatGetBytes 11
+pixelFormatGetBShift = pixelFormatGetBytes 12
+pixelFormatGetAShift = pixelFormatGetBytes 13
+#endif
+
+pixelFormatGetRMask, pixelFormatGetGMask, pixelFormatGetBMask, pixelFormatGetAMask :: SDL.PixelFormat -> IO Word32
+#ifdef ARCH_64
+pixelFormatGetRMask = pixelFormatGetBytes 20
+pixelFormatGetGMask = pixelFormatGetBytes 24
+pixelFormatGetBMask = pixelFormatGetBytes 28
+pixelFormatGetAMask = pixelFormatGetBytes 32
+#endif
+#ifdef ARCH_32
+pixelFormatGetRMask = pixelFormatGetBytes 16
+pixelFormatGetGMask = pixelFormatGetBytes 20
+pixelFormatGetBMask = pixelFormatGetBytes 24
+pixelFormatGetAMask = pixelFormatGetBytes 28
+#endif
+
+getPixel32 :: Int -> Int -> SDL.Surface -> IO SDL.Pixel
+getPixel32 x y s = do
+    pixels <- castPtr `liftM` SDL.surfaceGetPixels s
+    SDL.Pixel `liftM` peekElemOff pixels ((y * SDL.surfaceGetWidth s) + x)
+
+putPixel32 :: Int -> Int -> SDL.Pixel -> SDL.Surface -> IO ()
+putPixel32 x y (SDL.Pixel pixel) s = do
+    pixels <- castPtr `liftM` SDL.surfaceGetPixels s
+    pokeElemOff pixels ((y * SDL.surfaceGetWidth s) + x) pixel