-- #hide
--------------------------------------------------------------------------------
-- |
-- Module      :  Graphics.Rendering.OpenGL.GL.PixelData
-- Copyright   :  (c) Sven Panne 2002-2006
-- License     :  BSD-style (see the file libraries/OpenGL/LICENSE)
-- 
-- Maintainer  :  sven.panne@aedion.de
-- Stability   :  stable
-- Portability :  portable
--
-- This is a purely internal helper module.
--
--------------------------------------------------------------------------------

module Graphics.Rendering.OpenGL.GL.PixelData (
   PixelData(..), withPixelData
) where

import Foreign.Ptr ( Ptr )
import Graphics.Rendering.OpenGL.GL.BasicTypes ( GLenum )
import Graphics.Rendering.OpenGL.GL.DataType ( DataType, marshalDataType )
import Graphics.Rendering.OpenGL.GL.PixelFormat (
   PixelFormat, marshalPixelFormat )

--------------------------------------------------------------------------------

data PixelData a = PixelData PixelFormat DataType (Ptr a)
#ifdef __HADDOCK__
-- Help Haddock a bit, because it doesn't do any instance inference.
instance Eq (PixelData a)
instance Ord (PixelData a)
instance Show (PixelData a)
#else
   deriving ( Eq, Ord, Show )
#endif

withPixelData :: PixelData a -> (GLenum -> GLenum -> Ptr a -> b) -> b
withPixelData (PixelData pixelFormat dataType ptr) f =
   f (marshalPixelFormat pixelFormat) (marshalDataType dataType) ptr
