1 files changed, 126 insertions, 0 deletions
diff --git a/Graphics/SDL/SDLHelp.hs b/Graphics/SDL/SDLHelp.hs
new file mode 100644
index 0000000..8b09484
--- /dev/null
+++ b/Graphics/SDL/SDLHelp.hs
@@ -0,0 +1,126 @@
+module Graphics.SDL.SDLHelp where
+
+import Graphics.UI.SDL.Image as SDLImg
+import Graphics.UI.SDL as SDL 
+import Data.Word
+import Control.Monad
+import Graphics.Glyph.Util
+
+import Graphics.Rendering.OpenGL as GL
+import Graphics.Rendering.OpenGL.Raw.Core31
+
+import Foreign.Storable
+import Foreign.Ptr
+import Data.Bits
+
+import System.IO.Unsafe
+import System.Endian
+import System.Exit
+
+data TextureData = TextureData {
+    textureSize :: (Int,Int),
+    textureObject :: TextureObject } deriving Show
+
+bindSurfaceToTexture :: SDL.Surface -> TextureObject -> IO TextureData
+bindSurfaceToTexture surf to = do
+    textureBinding Texture2D $= Just to
+    bbp <- liftM fromIntegral (pixelFormatGetBytesPerPixel $ surfaceGetPixelFormat surf)
+    putStrLn $ "bpp: " ++! bbp
+    ptr <- surfaceGetPixels surf
+    glTexImage2D gl_TEXTURE_2D 0 bbp (w surf) (h surf) 0 (if bbp == 3 then gl_RGB else gl_RGBA) gl_UNSIGNED_BYTE ptr
+    return $ TextureData (w surf, h surf) to
+    where 
+          w :: (Integral a) => SDL.Surface -> a
+          w = fromIntegral . surfaceGetWidth
+          h :: (Integral a) => SDL.Surface -> a
+          h = fromIntegral . surfaceGetHeight
+
+textureFromSurface :: SDL.Surface -> IO TextureData
+textureFromSurface surf = makeTexture >>= (bindSurfaceToTexture surf >=> return)
+
+makeTexture :: IO TextureObject
+makeTexture = do
+    texobj <- liftM head $ genObjectNames 1
+    textureBinding Texture2D $= Just texobj
+    textureFilter Texture2D $= ((Linear', Nothing), Linear')
+    return texobj
+
+getPixel :: Int -> Int -> SDL.Surface -> IO Word32
+getPixel x y surf = do
+    bpp <- liftM fromIntegral (pixelFormatGetBytesPerPixel $ surfaceGetPixelFormat surf)
+    ptr <- (surfaceGetPixels surf >>= return.castPtr) :: IO (Ptr Word8)
+    let newPtr = ptr `plusPtr` (y * (fromIntegral $ surfaceGetPitch surf)) `plusPtr` (x * bpp)
+    
+    ret <- case bpp of
+        -- bytes = R G B A
+        1 -> liftM fromIntegral $ peek (castPtr newPtr :: Ptr Word8)
+        2 -> liftM fromIntegral $ peek (castPtr newPtr :: Ptr Word16)
+        3 -> do
+            ord1 <- liftM fromIntegral $ peek (castPtr newPtr :: Ptr Word16)
+            ord2 <- liftM fromIntegral $ peek (castPtr (newPtr `plusPtr` 2) :: Ptr Word8)
+            return $ ((ord1 `shiftL` 16) + (ord2 `shiftL` 8)) + 0xFF
+        4 -> do
+            liftM fromIntegral $ peek (castPtr newPtr :: Ptr Word32)
+        _ -> error "Unrecognized format"
+
+    return $ toBE32 ret
+
+getPixelUnsafe :: Int -> Int -> SDL.Surface -> Word32
+getPixelUnsafe x y surf = unsafePerformIO $ getPixel x y surf
+
+rgbToWord :: Word8 -> Word8 -> Word8 -> Word32
+rgbToWord r g b =
+    let tW32 x = (fromIntegral x) :: Word32 in
+    ( (tW32 r) `shiftL` 24) +
+    ( (tW32 g) `shiftL` 16) +
+    ( (tW32 b) `shiftL`  8) +
+    0xFF 
+
+wordToPixel :: Word32 -> Color4 Word8
+wordToPixel word =
+        Color4 (fromIntegral $ word .&. 0xFF)
+               (fromIntegral $ (word `shiftR` 8) .&. 0xFF)
+               (fromIntegral $ (word `shiftR` 16) .&. 0xFF)
+               (fromIntegral $ (word `shiftR` 24) .&. 0xFF)
+
+getRGBA :: SDL.Surface -> Int -> Int -> IO (Color4 Word8)
+getRGBA surf x y = liftM wordToPixel $ getPixel x y surf
+
+simpleStartup :: String -> (Int,Int) -> IO Surface
+simpleStartup name' (w,h) = do
+        SDL.init [SDL.InitEverything]
+        SDL.setVideoMode w h 32 [SDL.OpenGL, SDL.Resizable, SDL.DoubleBuf]
+        SDL.setCaption name' name'
+        SDL.getVideoSurface
+
+defaultReshape :: Int -> Int -> a -> IO a
+defaultReshape w h ret = do
+    let size = Size (fromIntegral w) (fromIntegral h)
+    viewport $=(Position 0 0, size)
+    _ <- SDL.setVideoMode w h 32 [SDL.OpenGL, SDL.Resizable, SDL.DoubleBuf]
+    return ret
+
+startPipeline :: (Int -> Int -> a -> IO a) -> (Event -> a -> IO a) -> (a -> IO a) -> (a -> IO a) -> a -> IO ()
+startPipeline reshapeH eventH displayH updateH ini = do
+    let pumpEvents' res = do
+        ev <- SDL.pollEvent
+        case ev of
+            Quit -> do
+                putStrLn "Exit event."
+                exitSuccess
+            SDL.NoEvent -> return res
+            VideoResize w h -> reshapeH w h res >>= pumpEvents'
+            _ -> eventH ev res >>= pumpEvents'
+    let runPipeline val = do
+            res <- pumpEvents' val >>= displayH
+            SDL.glSwapBuffers `seq` (updateH res) >>= runPipeline
+
+    -- TODO unhardcode this
+    reshapeH 640 480 ini >>= runPipeline
+
+setupTexturing :: TextureData -> UniformLocation -> Int -> IO ()
+setupTexturing (TextureData _ to) tu unit = do
+    texture Texture2D $= Enabled
+    activeTexture $= TextureUnit (fromIntegral unit)
+    textureBinding Texture2D $= Just to
+    uniform tu $= Index1 (fromIntegral unit::GLint)