    -- #hide
    --------------------------------------------------------------------------------
    -- |
    -- Module      :  Graphics.Rendering.OpenGL.GL.PolygonMode
    -- Copyright   :  (c) Sven Panne 2002-2009
    -- License     :  BSD-style (see the file libraries/OpenGL/LICENSE)
    --
    -- Maintainer  :  sven.panne@aedion.de
    -- Stability   :  stable
    -- Portability :  portable
    --
    -- This is a purely internal module for (un-)marshaling PolygonMode.
    --
    --------------------------------------------------------------------------------

    module Graphics.Rendering.OpenGL.GL.PolygonMode (
       PolygonMode(..), marshalPolygonMode, unmarshalPolygonMode
    ) where

    import Graphics.Rendering.OpenGL.GL.BasicTypes ( GLenum )

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

    data PolygonMode =
         Point
       | Line
       | Fill
       deriving ( Eq, Ord, Show )

    marshalPolygonMode :: PolygonMode -> GLenum
    marshalPolygonMode x = case x of
       Point -> 0x1b00
       Line -> 0x1b01
       Fill -> 0x1b02

    unmarshalPolygonMode :: GLenum -> PolygonMode
    unmarshalPolygonMode x
       | x == 0x1b00 = Point
       | x == 0x1b01 = Line
       | x == 0x1b02 = Fill
       | otherwise = error ("unmarshalPolygonMode: illegal value " ++ show x)