-- |
--
-- Module      : SDL.ImageFilter
-- Copyright   : (c) 2015 Siniša Biđin
-- License     : MIT
-- Maintainer  : sinisa@bidin.eu
-- Stability   : experimental
--
-- Bindings to @SDL2_gfx@'s MMX image filter functionality.
module SDL.ImageFilter
  ( -- * Query MMX
    usingMMX,
    disableMMX,
    enableMMX,

    -- * Vector operations
    add,
    mean,
    sub,
    absDiff,
    mult,
    multNor,
    multDivBy2,
    multDivBy4,
    bitAnd,
    bitOr,
    div,
    bitNegation,
    addByte,
    addUInt,
    addByteToHalf,
    subByte,
    subUInt,
    shiftRight,
    shiftRightUInt,
    multByByte,
    shiftRightAndMultByByte,
    shiftLeftByte,
    shiftLeftUInt,
    shiftLeft,
    binarizeUsingThreshold,
    clipToRange,
    normalizeLinear,
  )
where

import Control.Monad.IO.Class (MonadIO, liftIO)
import Data.Vector.Storable (Vector)
import qualified Data.Vector.Storable as V
import Data.Word (Word8)
import Foreign.C.Types (CInt, CUChar, CUInt)
import Foreign.ForeignPtr (newForeignPtr)
import Foreign.Marshal.Alloc (finalizerFree, mallocBytes)
import Foreign.Ptr (Ptr, castPtr)
import qualified SDL.Raw.ImageFilter
import System.IO.Unsafe (unsafePerformIO)
import Prelude hiding (div)

-- | Are we using MMX code?
usingMMX :: MonadIO m => m Bool
usingMMX = (== 1) <$> SDL.Raw.ImageFilter.mmxDetect

-- | Disable MMX, use non-MMX code instead.
disableMMX :: MonadIO m => m ()
disableMMX = liftIO SDL.Raw.ImageFilter.mmxOff

-- | Use MMX code if available.
enableMMX :: MonadIO m => m ()
enableMMX = liftIO SDL.Raw.ImageFilter.mmxOn

{-# INLINE minLen #-}
minLen :: Integral a => Vector Word8 -> Vector Word8 -> a
minLen x = fromIntegral . min (V.length x) . V.length

mallocVector :: Int -> (Ptr CUChar -> IO a) -> IO (Vector Word8)
mallocVector len act = do
  p <- mallocBytes len
  _ <- act p -- TODO: Check for errors?
  f <- newForeignPtr finalizerFree $ castPtr p
  return $ V.unsafeFromForeignPtr0 f len

binary ::
  (Ptr CUChar -> Ptr CUChar -> Ptr CUChar -> CUInt -> IO CInt) ->
  (Vector Word8 -> Vector Word8 -> Vector Word8)
binary f x y =
  unsafePerformIO
    . V.unsafeWith x
    $ \x' ->
      V.unsafeWith y $ \y' ->
        mallocVector (minLen x y) $ \z' ->
          f (castPtr x') (castPtr y') z' (minLen x y)

add :: Vector Word8 -> Vector Word8 -> Vector Word8
add = binary SDL.Raw.ImageFilter.add

mean :: Vector Word8 -> Vector Word8 -> Vector Word8
mean = binary SDL.Raw.ImageFilter.mean

sub :: Vector Word8 -> Vector Word8 -> Vector Word8
sub = binary SDL.Raw.ImageFilter.sub

absDiff :: Vector Word8 -> Vector Word8 -> Vector Word8
absDiff = binary SDL.Raw.ImageFilter.absDiff

mult :: Vector Word8 -> Vector Word8 -> Vector Word8
mult = binary SDL.Raw.ImageFilter.mult

multNor :: Vector Word8 -> Vector Word8 -> Vector Word8
multNor = binary SDL.Raw.ImageFilter.multNor

multDivBy2 :: Vector Word8 -> Vector Word8 -> Vector Word8
multDivBy2 = binary SDL.Raw.ImageFilter.multDivBy2

multDivBy4 :: Vector Word8 -> Vector Word8 -> Vector Word8
multDivBy4 = binary SDL.Raw.ImageFilter.multDivBy4

bitAnd :: Vector Word8 -> Vector Word8 -> Vector Word8
bitAnd = binary SDL.Raw.ImageFilter.bitAnd

bitOr :: Vector Word8 -> Vector Word8 -> Vector Word8
bitOr = binary SDL.Raw.ImageFilter.bitOr

div :: Vector Word8 -> Vector Word8 -> Vector Word8
div = binary SDL.Raw.ImageFilter.div

{-# INLINE cuchar #-}
cuchar :: Word8 -> CUChar
cuchar = fromIntegral

bitNegation :: Vector Word8 -> Vector Word8
bitNegation x =
  unsafePerformIO
    . V.unsafeWith x
    $ \x' ->
      mallocVector (V.length x) $ \y' ->
        SDL.Raw.ImageFilter.bitNegation
          (castPtr x')
          y'
          (fromIntegral $ V.length x)

binaryByte ::
  (Ptr CUChar -> Ptr CUChar -> CUInt -> CUChar -> IO CInt) ->
  (Word8 -> Vector Word8 -> Vector Word8)
binaryByte f b x =
  unsafePerformIO
    . V.unsafeWith x
    $ \x' ->
      mallocVector (V.length x) $ \y' ->
        f (castPtr x') y' (fromIntegral $ V.length x) (cuchar b)

addByte :: Word8 -> Vector Word8 -> Vector Word8
addByte = binaryByte SDL.Raw.ImageFilter.addByte

addByteToHalf :: Word8 -> Vector Word8 -> Vector Word8
addByteToHalf = binaryByte SDL.Raw.ImageFilter.addByteToHalf

subByte :: Word8 -> Vector Word8 -> Vector Word8
subByte = binaryByte SDL.Raw.ImageFilter.subByte

shiftRight :: Word8 -> Vector Word8 -> Vector Word8
shiftRight = binaryByte SDL.Raw.ImageFilter.shiftRight

multByByte :: Word8 -> Vector Word8 -> Vector Word8
multByByte = binaryByte SDL.Raw.ImageFilter.multByByte

shiftLeftByte :: Word8 -> Vector Word8 -> Vector Word8
shiftLeftByte = binaryByte SDL.Raw.ImageFilter.shiftLeftByte

shiftRightUInt :: Word8 -> Vector Word8 -> Vector Word8
shiftRightUInt = binaryByte SDL.Raw.ImageFilter.shiftRightUInt

shiftLeftUInt :: Word8 -> Vector Word8 -> Vector Word8
shiftLeftUInt = binaryByte SDL.Raw.ImageFilter.shiftLeftUInt

shiftLeft :: Word8 -> Vector Word8 -> Vector Word8
shiftLeft = binaryByte SDL.Raw.ImageFilter.shiftLeft

binarizeUsingThreshold :: Word8 -> Vector Word8 -> Vector Word8
binarizeUsingThreshold = binaryByte SDL.Raw.ImageFilter.binarizeUsingThreshold

binaryUInt ::
  (Ptr CUChar -> Ptr CUChar -> CUInt -> CUInt -> IO CInt) ->
  (CUInt -> Vector Word8 -> Vector Word8)
binaryUInt f i x =
  unsafePerformIO
    . V.unsafeWith x
    $ \x' ->
      mallocVector (V.length x) $ \y' ->
        f (castPtr x') y' (fromIntegral $ V.length x) i

addUInt :: CUInt -> Vector Word8 -> Vector Word8
addUInt = binaryUInt SDL.Raw.ImageFilter.addUInt

subUInt :: CUInt -> Vector Word8 -> Vector Word8
subUInt = binaryUInt SDL.Raw.ImageFilter.subUInt

shiftRightAndMultByByte :: Word8 -> Word8 -> Vector Word8 -> Vector Word8
shiftRightAndMultByByte s m x =
  unsafePerformIO
    . V.unsafeWith x
    $ \x' ->
      mallocVector (V.length x) $ \y' ->
        SDL.Raw.ImageFilter.shiftRightAndMultByByte
          (castPtr x')
          y'
          (fromIntegral $ V.length x)
          (cuchar s)
          (cuchar m)

clipToRange :: Word8 -> Word8 -> Vector Word8 -> Vector Word8
clipToRange a b x =
  unsafePerformIO
    . V.unsafeWith x
    $ \x' ->
      mallocVector (V.length x) $ \y' ->
        SDL.Raw.ImageFilter.clipToRange
          (castPtr x')
          y'
          (fromIntegral $ V.length x)
          (cuchar a)
          (cuchar b)

normalizeLinear :: CInt -> CInt -> CInt -> CInt -> Vector Word8 -> Vector Word8
normalizeLinear cmin cmax nmin nmax x =
  unsafePerformIO
    . V.unsafeWith x
    $ \x' ->
      mallocVector (V.length x) $ \y' ->
        SDL.Raw.ImageFilter.normalizeLinear
          (castPtr x')
          y'
          (fromIntegral $ V.length x)
          cmin
          cmax
          nmin
          nmax