-- Hoogle documentation, generated by Haddock
-- See Hoogle, http://www.haskell.org/hoogle/


-- | Miscellaneous OpenGL utilities.
--   
--   Helpers for working with shaders, buffer objects, and textures in
--   OpenGL.
@package GLUtil
@version 0.2


-- | A thin layer over OpenGL 3.1+ vertex array objects.
module Graphics.GLUtil.VertexArrayObjects

-- | A vertex array object captures OpenGL state needed for drawing a
--   vertex array. It encapsulates the binding of an array buffer and an
--   element buffer, as well as vertex attribute setup.
newtype VertexArrayObject
VertexArrayObject :: GLuint -> VertexArrayObject

-- | Short alias.
type VAO = VertexArrayObject

-- | Allocate a <a>VertexArrayObject</a>, and initialize it with the
--   provided action. This action should bind the buffer data, index data
--   (if necessary), and setup vertex attributes.
makeVAO :: IO () -> IO VertexArrayObject

-- | Delete a <a>VertexArrayObject</a>. Do not use the VAO after running
--   this action!
deleteVAO :: VertexArrayObject -> IO ()

-- | Bind a <a>VertexArrayObject</a>, or ensure that no VAO is bound.
bindVertexArray :: Maybe VertexArrayObject -> IO ()


-- | Miscellaneous utilities for dealing with OpenGL errors.
module Graphics.GLUtil.GLError

-- | Check OpenGL error flags and print them on <a>stderr</a>.
printError :: IO ()

-- | Check OpenGL error flags and print them on <a>stderr</a> with the
--   given message as a prefix. If there are no errors, nothing is printed.
printErrorMsg :: String -> IO ()

-- | Throw an exception if there is an OpenGL error.
throwError :: IO ()

-- | An exception type for OpenGL errors.
data GLError

-- | Throw an exception if there is an OpenGL error. The exception's error
--   message is prefixed with the supplied <a>String</a>.
throwErrorMsg :: String -> IO ()
instance Typeable GLError
instance Show GLError
instance Exception GLError


-- | Utilities for loading texture data.
module Graphics.GLUtil.Textures

-- | Pixel format of image data.
data TexColor
TexMono :: TexColor
TexRGB :: TexColor
TexBGR :: TexColor

-- | A basic texture information record.
data TexInfo a
TexInfo :: GLsizei -> GLsizei -> TexColor -> a -> TexInfo a
texWidth :: TexInfo a -> GLsizei
texHeight :: TexInfo a -> GLsizei
texColor :: TexInfo a -> TexColor
texData :: TexInfo a -> a

-- | Helper for constructing a <a>TexInfo</a> using Haskell <a>Int</a>s for
--   image dimensions.
texInfo :: Int -> Int -> TexColor -> a -> TexInfo a

-- | Open mapping from Haskell types to OpenGL types.
class Storable a => HasGLType a
glType :: HasGLType a => a -> DataType

-- | Class for containers of texture data.
class HasGLType (Elem a) => IsPixelData a where type family Elem a
withPixels :: IsPixelData a => a -> (Ptr (Elem a) -> IO c) -> IO c

-- | Wrapper whose <a>IsPixelData</a> instance treats the pointer
--   underlying a <a>ByteString</a> as an array of <a>Word16</a>s.
newtype ShortString
ShortString :: ByteString -> ShortString

-- | Create a new 2D texture with data from a <a>TexInfo</a>.
loadTexture :: IsPixelData a => TexInfo a -> IO (TextureObject)

-- | Replace a 2D texture's pixel data with data from a <a>TexInfo</a>.
reloadTexture :: IsPixelData a => TextureObject -> TexInfo a -> IO ()
instance IsPixelData ShortString
instance IsPixelData ByteString
instance HasGLType b => IsPixelData (Vector b)
instance HasGLType b => IsPixelData (StorableArray i b)
instance HasGLType b => IsPixelData (ForeignPtr b)
instance HasGLType b => IsPixelData (Ptr b)
instance HasGLType b => IsPixelData [b]
instance HasGLType Float
instance HasGLType Word16
instance HasGLType Word8
instance HasGLType Int


-- | Utilities for working with fragment and vertex shader programs.
module Graphics.GLUtil.Shaders

-- | Load a shader program from a file.
loadShader :: Shader s => FilePath -> IO s

-- | Link vertex and fragment shaders into a <a>Program</a>.
linkShaderProgram :: [VertexShader] -> [FragmentShader] -> IO Program

-- | Work with a named uniform shader parameter. Note that this looks up
--   the variable name on each access, so uniform parameters that will be
--   accessed frequently should instead be resolved to a
--   <a>UniformLocation</a>.
namedUniform :: Uniform a => String -> StateVar a

-- | Set a <a>UniformLocation</a> to a scalar value.
uniformScalar :: UniformComponent a => UniformLocation -> SettableStateVar a

-- | Set a <a>UniformLocation</a> from a list representation of a
--   low-dimensional vector of <a>GLfloat</a>s. Only 2, 3, and 4
--   dimensional vectors are supported.
uniformVec :: UniformLocation -> SettableStateVar [GLfloat]

-- | Set a uniform shader location from a nested list matrix
--   representation. Only 3x3 and 4x4 matrices are supported.
uniformMat :: UniformLocation -> SettableStateVar [[GLfloat]]

-- | Set a named uniform shader parameter from a nested list matrix
--   representation. Only 3x3 and 4x4 matrices are supported.
namedUniformMat :: String -> SettableStateVar [[GLfloat]]

-- | Set a uniform shader location with a 4x4 <a>GLmatrix</a>.
uniformGLMat4 :: UniformLocation -> SettableStateVar (GLmatrix GLfloat)


-- | Utilities for filling <a>BufferObject</a>s.
module Graphics.GLUtil.BufferObjects

-- | Allocate and fill a <a>BufferObject</a> from a list of
--   <a>Storable</a>s.
makeBuffer :: Storable a => BufferTarget -> [a] -> IO BufferObject

-- | Allocate and fill a <a>BufferObject</a> from a list of
--   <a>Storable</a>s whose length is explicitly given. This is useful when
--   the list is of known length, as it avoids a traversal to find the
--   length.
makeBufferLen :: Storable a => BufferTarget -> Int -> [a] -> IO BufferObject

-- | Allocate and fill a <a>BufferObject</a> with the given number of bytes
--   from the supplied pointer.
fromPtr :: BufferTarget -> Int -> Ptr a -> IO BufferObject

-- | Fill a buffer with a <a>ByteString</a>.
fromByteString :: BufferTarget -> ByteString -> IO BufferObject

-- | Fill a buffer with data from a <a>ForeignPtr</a>. The application
--   <tt>fromForeignPtr target len fptr</tt> fills a <tt>target</tt>
--   <a>BufferTarget</a> with <tt>len</tt> elements starting from
--   <tt>fptr</tt>.
fromForeignPtr :: Storable a => BufferTarget -> Int -> ForeignPtr a -> IO BufferObject

-- | Fill a buffer with data from a <a>Vector</a>.
fromVector :: Storable a => BufferTarget -> Vector a -> IO BufferObject

-- | Produce a <a>Ptr</a> value to be used as an offset of the given number
--   of bytes.
offsetPtr :: Int -> Ptr a

-- | A zero-offset <a>Ptr</a>.
offset0 :: Ptr a


-- | The main import that simply re-exports the various modules that make
--   up the <tt>GLUtil</tt> library.
module Graphics.GLUtil