    --------------------------------------------------------------------------------
    -- |
    -- Module      :  Graphics.Rendering.OpenGL.GL.BasicTypes
    -- 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 module corresponds to section 2.3 (GL Command Sytax) of the OpenGL 2.1
    -- specs.
    --
    --------------------------------------------------------------------------------

    module Graphics.Rendering.OpenGL.GL.BasicTypes (
       GLboolean, GLbyte, GLubyte, GLchar, GLshort, GLushort, GLint, GLuint,
       GLsizei, GLenum, GLintptr, GLsizeiptr, GLbitfield, GLfloat, GLclampf,
       GLdouble, GLclampd, Capability(..)
    ) where

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

    #include "HsOpenGLConfig.h"

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

    import Data.Int
    import Data.Word

    -- If we don't find modern OpenGL headers at configuration time, make some
    -- educated guesses here.

    #if !defined(HTYPE_GLCHAR) || !defined(HTYPE_GLINTPTR) || !defined(HTYPE_GLSIZEIPTR)
    import Foreign.C.Types
    #endif

    #if !defined(HTYPE_GLCHAR)
    #define HTYPE_GLCHAR CChar
    #endif

    #if !defined(HTYPE_GLINTPTR)
    #define HTYPE_GLINTPTR CPtrdiff
    #endif

    #if !defined(HTYPE_GLSIZEIPTR)
    #define HTYPE_GLSIZEIPTR CPtrdiff
    #endif

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

    -- | Boolean (min. 1 bit)
    type GLboolean = HTYPE_GLBOOLEAN

    -- | Signed 2\'s complement binary integer (min. 8 bits)
    type GLbyte = HTYPE_GLBYTE

    -- | Unsigned binary integer (min. 8 bits)
    type GLubyte = HTYPE_GLUBYTE

    -- | Characters making up strings
    type GLchar = HTYPE_GLCHAR

    -- | Signed 2\'s complement binary integer (min. 16 bits)
    type GLshort = HTYPE_GLSHORT

    -- | Unsigned binary integer (min. 16 bits)
    type GLushort = HTYPE_GLUSHORT

    -- | Signed 2\'s complement binary integer (min. 32 bits)
    type GLint = HTYPE_GLINT

    -- | Unsigned binary integer (min. 32 bits)
    type GLuint = HTYPE_GLUINT

    -- | Non-negatitve binary integer size (min. 32 bits)
    type GLsizei = HTYPE_GLSIZEI

    -- | Enumerated binary integer value (min. 32 bits)
    type GLenum = HTYPE_GLENUM

    -- | Signed 2\'s complement binary integer (sufficiently large enough to hold
    -- any address)
    type GLintptr = HTYPE_GLINTPTR

    -- | Non-negatitve binary integer size (sufficiently large enough to hold any
    -- address)
    type GLsizeiptr = HTYPE_GLSIZEIPTR

    -- | Bit field (min. 32 bits)
    type GLbitfield = HTYPE_GLBITFIELD

    -- | Floating-point value (min. 32 bits)
    type GLfloat = HTYPE_GLFLOAT

    -- | Floating-point value clamped to [0,1] (min. 32 bits)
    type GLclampf = HTYPE_GLCLAMPF

    -- | Floating-point value (min. 64 bits)
    type GLdouble = HTYPE_GLDOUBLE

    -- | Floating-point value clamped to [0,1] (min. 64 bits)
    type GLclampd = HTYPE_GLCLAMPD

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

    data Capability =
         Disabled
       | Enabled
       deriving ( Eq, Ord, Show )