diff --git a/Changes b/Changes
--- a/Changes
+++ b/Changes
@@ -1,4 +1,15 @@
 
+version 0.6.0 (17 Jan 2010):
+  * Revised the RenderingQuality module to use an opaque matrix
+    type rather than a raw pointer. Acknowledgement - the code 
+    and interface is derived from the Matrix class in HOpenGL.
+  
+  * Revised Image module - PixelData is now an opaque type rather
+    than a raw pointer.
+
+  * Work on Path module - pathBounds implemented. This module is
+    entirely untested and may change again in the future.
+
 version 0.5.0 (16 Jan 2010):
   * Split into 2 packages OpenVG (this package) and OpenVGRaw.
 
diff --git a/OpenVG.cabal b/OpenVG.cabal
--- a/OpenVG.cabal
+++ b/OpenVG.cabal
@@ -1,5 +1,5 @@
 name:             OpenVG
-version:          0.5.0
+version:          0.6.0
 license:          BSD3
 license-file:     LICENSE
 copyright:        Stephen Tetley <stephen.tetley@gmail.com>
@@ -11,41 +11,28 @@
   A Haskell binding for the OpenVG vector graphics API version 
   1.0.1, specifically the ShivaVG-0.2.1 implementation.
   .
-  This version (0.5.0) is NOT compatible with the Haskell Platform 
+  This version (0.6.0) is NOT compatible with the Haskell Platform 
   (2009.2.0.2) - it uses the split OpenGL packages (RAW, StateVar, 
   etc.).
   .
-  \*\* WARNING - major changes to previous version. Also 
-  significant changes likely in next revision. \*\*.
+  \*\* WARNING - large parts of the API (particular the Paths 
+  module) are untested and may be revised in future. \*\*.
   .
   Changelog
-  0.4.0 to 0.5.0
-  . 
-  * Significantly reworked. Changed to use OpenVGRaw. 
   .
+  0.5.0 to 0.6.0
   .
-  0.3.0 to 0.4.0 
+  * Added an opaque matrix type to RenderingQuality. 
+    Acknowledgement - this was derived from the Matrix class
+    in HOpenGL.
   .
-  * LinearGradient type changed to be Vector4 VGfloat.
-  . 
-  * RadialGradient changed to (Vector4 VGfloat, VGfloat).
+  * Revised Image module - PixelData is now an opaque type rather
+    than a raw pointer.
   .
-  * Removed Marshal and Unmarshal type classes, marshallBool and 
-    unmarshalBool moved out of the BasicTypes module.
+  * Work on Path module - pathBounds implemented. This module is
+    entirely untested and may change again in the future.
   .
-  * Type change for colorRampStops.
   .
-  * Name change - maxStops changed to maxColorRampStops.
-  .
-  * PathType(..) changed to PathAbsRel(..).
-  . 
-  * Substantial changes to Haddock docs.
-  .
-  * Error handling in VGU redone - the original code in 
-    ErrorsInternal was taken wholesale from Sven Panne\'s 
-    OpenGL binding to help me bootstrap the OpenVG binding. 
-    Regrettably I forgot to replace it or attribute it -
-    I've now replaced it. Sincere apologies to Sven Panne.
  
 build-type:         Simple
 stability:          experimental
@@ -66,7 +53,7 @@
                       OpenGLRaw >= 1.1.0.1 && < 2, 
                       StateVar  >= 1.0.0.0 && < 2,
                       Tensor    >= 1.0.0.1 && < 2,
-                      OpenVGRaw >= 0.1.0
+                      OpenVGRaw >= 0.2.0
   
   exposed-modules:
     Graphics.Rendering.OpenVG,
diff --git a/demo/VguUtils.hs b/demo/VguUtils.hs
--- a/demo/VguUtils.hs
+++ b/demo/VguUtils.hs
@@ -34,7 +34,8 @@
 
 
 testCreatePath :: IO VGPath
-testCreatePath = createPath VG.Float 1.0 0.0 0 0 [CapabilityAll]
+testCreatePath = 
+    createPath (PathProperties VG.Float 1.0 0.0 0 0 [CapabilityAll])
 
 testDestoryPaths :: [VGPath] -> IO ()
 testDestoryPaths = mapM_ destroyPath
diff --git a/src/Graphics/Rendering/OpenVG/VG.hs b/src/Graphics/Rendering/OpenVG/VG.hs
--- a/src/Graphics/Rendering/OpenVG/VG.hs
+++ b/src/Graphics/Rendering/OpenVG/VG.hs
@@ -3,7 +3,7 @@
 --------------------------------------------------------------------------------
 -- |
 -- Module      :  Graphics.Rendering.OpenVG.VG
--- Copyright   :  (c) Stephen Tetley 2008, 2009
+-- Copyright   :  (c) Stephen Tetley 2008-2010
 -- License     :  BSD3
 --
 -- Maintainer  :  Stephen Tetley <stephen.tetley@gmail.com>
diff --git a/src/Graphics/Rendering/OpenVG/VG/Blending.hs b/src/Graphics/Rendering/OpenVG/VG/Blending.hs
--- a/src/Graphics/Rendering/OpenVG/VG/Blending.hs
+++ b/src/Graphics/Rendering/OpenVG/VG/Blending.hs
@@ -3,7 +3,7 @@
 --------------------------------------------------------------------------------
 -- |
 -- Module      :  Graphics.Rendering.OpenVG.VG.Blending
--- Copyright   :  (c) Stephen Tetley 2008, 2009
+-- Copyright   :  (c) Stephen Tetley 2008-2010
 -- License     :  BSD3
 --
 -- Maintainer  :  Stephen Tetley <stephen.tetley@gmail.com>
diff --git a/src/Graphics/Rendering/OpenVG/VG/DrawingContext.hs b/src/Graphics/Rendering/OpenVG/VG/DrawingContext.hs
--- a/src/Graphics/Rendering/OpenVG/VG/DrawingContext.hs
+++ b/src/Graphics/Rendering/OpenVG/VG/DrawingContext.hs
@@ -3,7 +3,7 @@
 --------------------------------------------------------------------------------
 -- |
 -- Module      :  Graphics.Rendering.OpenVG.VG.ShivaExtensions
--- Copyright   :  (c) Stephen Tetley 2008, 2009
+-- Copyright   :  (c) Stephen Tetley 2008-2010
 -- License     :  BSD3
 --
 -- Maintainer  :  Stephen Tetley <stephen.tetley@gmail.com>
diff --git a/src/Graphics/Rendering/OpenVG/VG/Extending.hs b/src/Graphics/Rendering/OpenVG/VG/Extending.hs
--- a/src/Graphics/Rendering/OpenVG/VG/Extending.hs
+++ b/src/Graphics/Rendering/OpenVG/VG/Extending.hs
@@ -3,7 +3,7 @@
 --------------------------------------------------------------------------------
 -- |
 -- Module      :  Graphics.Rendering.OpenVG.VG.Extending
--- Copyright   :  (c) Stephen Tetley 2008, 2009
+-- Copyright   :  (c) Stephen Tetley 2008-2010
 -- License     :  BSD3
 --
 -- Maintainer  :  Stephen Tetley <stephen.tetley@gmail.com>
diff --git a/src/Graphics/Rendering/OpenVG/VG/Images.hs b/src/Graphics/Rendering/OpenVG/VG/Images.hs
--- a/src/Graphics/Rendering/OpenVG/VG/Images.hs
+++ b/src/Graphics/Rendering/OpenVG/VG/Images.hs
@@ -3,7 +3,7 @@
 --------------------------------------------------------------------------------
 -- |
 -- Module      :  Graphics.Rendering.OpenVG.VG.Images
--- Copyright   :  (c) Stephen Tetley 2008, 2009
+-- Copyright   :  (c) Stephen Tetley 2008-2010
 -- License     :  BSD3
 --
 -- Maintainer  :  Stephen Tetley <stephen.tetley@gmail.com>
@@ -23,7 +23,12 @@
   
   -- * Image formats
   ImageFormat(..),
-  
+
+  -- * Pixel data
+  Stride,
+  PixelData,   
+
+
   -- * Creating and destroying images
   maxImageWidth, 
   maxImageHeight, 
@@ -49,7 +54,7 @@
   -- * Copying pixels between images
   copyImage, 
   
-  -- * Drawing iamges to the drawing surface
+  -- * Drawing images to the drawing surface
   ImageMode(..),
   drawImageMode, 
   drawImage,
@@ -160,6 +165,26 @@
    deriving ( Eq, Ord, Show )
   
 
+--------------------------------------------------------------------------------
+-- Pixel data
+
+
+-- Derived from HOpenGL
+-- NOTES - How do you create PixelData ?
+
+type Stride = VGint
+
+-- Opaque handle to pixel data. 
+--
+-- \*\* NOTE - ShivaVG currently only supports @sRGBA_8888@. \*\*
+--
+data PixelData a = PixelData ImageFormat Stride (Ptr a)
+   deriving ( Eq, Ord, Show )
+
+withPixelData :: PixelData a -> (VGenum -> Stride -> Ptr a -> b) -> b
+withPixelData (PixelData image_format stride ptr) f = 
+    f (marshalImageFormat image_format) stride ptr
+
     
 
 --------------------------------------------------------------------------------
@@ -216,6 +241,9 @@
 -- 'createImage' corresponds to the OpenVG function 
 -- @vgCreateImage@.
 --
+-- \*\* NOTE - ShivaVG currently only supports @sRGBA_8888@ - 
+-- this function throws a runtime error for other formats. \*\*
+--
 createImage :: ImageFormat -> Size -> [ImageQuality] -> IO VGImage 
 createImage SRGBA8888 sz qs = 
     unSizeM (\w h -> vgCreateImage (marshalImageFormat SRGBA8888)
@@ -303,10 +331,10 @@
 -- 'imageSubData' corresponds to the OpenVG function 
 -- @vgImageSubData@. 
 --
-imageSubData :: VGImage -> Ptr a -> VGint -> ImageFormat
-                  -> Position -> Size -> IO ()
-imageSubData image imgdata stride fmt (Position x y) =
-    unSizeM $ vgImageSubData image imgdata stride (marshalImageFormat fmt) x y
+imageSubData :: VGImage -> PixelData a -> Position -> Size -> IO ()
+imageSubData image pd (Position x y) =
+    unSizeM $ withPixelData pd $ \format_enum stride pixel_data -> 
+                vgImageSubData image pixel_data stride format_enum x y
 
 
 
@@ -316,10 +344,10 @@
 -- 'getImageSubData' corresponds to the OpenVG function 
 -- @vgGetImageSubData@. 
 --
-getImageSubData :: VGImage -> Ptr a -> VGint -> ImageFormat
-                    -> Position -> Size -> IO ()
-getImageSubData image imgdata stride fmt (Position x y) = 
-    unSizeM $ vgGetImageSubData image imgdata stride (marshalImageFormat fmt) x y
+getImageSubData :: VGImage -> PixelData a -> Position -> Size -> IO ()
+getImageSubData image pd (Position x y) = 
+    unSizeM $ withPixelData pd $ \format_enum stride pixel_data ->
+                vgGetImageSubData image pixel_data stride format_enum x y
    
 --------------------------------------------------------------------------------
 
@@ -333,13 +361,13 @@
 --
 -- 'copyImage' corresponds to the OpenVG function @vgCopyImage@.
 --
-copyImage :: VGImage -> Position -> VGImage -> Position
-                -> Size -> Bool -> IO ()
+copyImage :: VGImage -> Position -> VGImage -> Position -> Size -> Bool -> IO ()
 copyImage dst (Position dx dy) src (Position sx sy) sz dither = 
-    unSizeM (\w h -> vgCopyImage dst dx dy src sx sy w h (marshalBool dither)) sz
+    (unSizeM `flip` sz) $ \w h -> 
+        vgCopyImage dst dx dy src sx sy w h (marshalBool dither)
 
 --------------------------------------------------------------------------------
--- Drawing iamges to the drawing surface
+-- Drawing images to the drawing surface
 
 -- | Styles of image drawing   
 data ImageMode = 
@@ -372,6 +400,7 @@
 --------------------------------------------------------------------------------
 -- Reading and writing drawing surface pixels
 
+
 -- | Copy pixel data from the image to the drawing surface.
 --
 -- 'setPixels' corresponds to the OpenVG function @vgSetPixels@. 
@@ -385,15 +414,17 @@
 --
 -- 'writePixels' corresponds to the OpenVG function @vgWritePixels@.
 --
-writePixels :: Ptr a -> VGint -> ImageFormat -> Position -> Size -> IO ()
-writePixels pixeldata stride fmt (Position dx dy) =  
-    unSizeM $ vgWritePixels pixeldata stride (marshalImageFormat fmt) dx dy
+writePixels :: PixelData a -> Position -> Size -> IO ()
+writePixels pd (Position dx dy) = 
+    unSizeM $ withPixelData pd $ \format_enum stride pixel_data ->
+                vgWritePixels pixel_data stride format_enum dx dy
 
+
 -- | Retrieve pixel information from the drawing surface. 
 -- 
 -- 'getPixels' corresponds to the OpenVG function @vgGetPixels@.
 --
-getPixels :: VGImage  -> Position -> Position -> Size -> IO ()
+getPixels :: VGImage -> Position -> Position -> Size -> IO ()
 getPixels dst (Position dx dy) (Position sx sy) =  
     unSizeM $ vgGetPixels dst dx dy sx sy
 
@@ -402,9 +433,12 @@
 -- 
 -- 'readPixels' corresponds to the OpenVG function @vgReadPixels@.
 --
-readPixels :: Ptr a -> VGint -> ImageFormat -> Position -> Size -> IO ()
-readPixels pixeldata stride fmt (Position sx sy) = unSizeM $
-    vgReadPixels pixeldata stride (marshalImageFormat fmt) sx sy
+readPixels :: PixelData a -> Position -> Size -> IO ()
+readPixels pd (Position sx sy)  = 
+    unSizeM $ withPixelData pd $ \format_enum stride pixel_data -> 
+                vgReadPixels pixel_data stride format_enum sx sy 
+
+
 
 --------------------------------------------------------------------------------
 -- Copying portions of the drawing surface
diff --git a/src/Graphics/Rendering/OpenVG/VG/Paint.hs b/src/Graphics/Rendering/OpenVG/VG/Paint.hs
--- a/src/Graphics/Rendering/OpenVG/VG/Paint.hs
+++ b/src/Graphics/Rendering/OpenVG/VG/Paint.hs
@@ -3,7 +3,7 @@
 --------------------------------------------------------------------------------
 -- |
 -- Module      :  Graphics.Rendering.OpenVG.VG.Paint
--- Copyright   :  (c) Stephen Tetley 2008, 2009
+-- Copyright   :  (c) Stephen Tetley 2008-2010
 -- License     :  BSD3
 --
 -- Maintainer  :  Stephen Tetley <stephen.tetley@gmail.com>
diff --git a/src/Graphics/Rendering/OpenVG/VG/Parameters.hs b/src/Graphics/Rendering/OpenVG/VG/Parameters.hs
--- a/src/Graphics/Rendering/OpenVG/VG/Parameters.hs
+++ b/src/Graphics/Rendering/OpenVG/VG/Parameters.hs
@@ -1,10 +1,9 @@
-{-# LANGUAGE ForeignFunctionInterface #-}
 {-# OPTIONS -Wall #-}
 
 --------------------------------------------------------------------------------
 -- |
 -- Module      :  Graphics.Rendering.OpenVG.VG.Parameters
--- Copyright   :  (c) Stephen Tetley 2008, 2009
+-- Copyright   :  (c) Stephen Tetley 2008-2010
 -- License     :  BSD3
 --
 -- Maintainer  :  Stephen Tetley <stephen.tetley@gmail.com>
diff --git a/src/Graphics/Rendering/OpenVG/VG/Paths.hs b/src/Graphics/Rendering/OpenVG/VG/Paths.hs
--- a/src/Graphics/Rendering/OpenVG/VG/Paths.hs
+++ b/src/Graphics/Rendering/OpenVG/VG/Paths.hs
@@ -1,11 +1,10 @@
-{-# LANGUAGE ExistentialQuantification #-}
-{-# LANGUAGE TypeSynonymInstances #-}
+{-# LANGUAGE TypeSynonymInstances       #-}
 {-# OPTIONS -Wall #-}
 
 --------------------------------------------------------------------------------
 -- |
 -- Module      :  Graphics.Rendering.OpenVG.VG.Paths
--- Copyright   :  (c) Stephen Tetley 2008, 2009, 2010
+-- Copyright   :  (c) Stephen Tetley 2008-2010
 -- License     :  BSD3
 --
 -- Maintainer  :  Stephen Tetley <stephen.tetley@gmail.com>
@@ -15,12 +14,7 @@
 -- This module corresponds to section 8 (Paths) 
 -- of the OpenVG 1.0.1 specs.
 --
--- \*\* WARNING - this module is due to be changed significantly.
 --
--- This is unfortunate as the module defines the most significant 
--- data types for vectors - the @Paths@. \*\*
---
---
 --------------------------------------------------------------------------------
 
 
@@ -34,16 +28,19 @@
   
   -- * Creating and destroying paths
   PathCapabilities(..),
+  PathProperties(..),
+
   withPath,
   createPath, 
   clearPath, 
   destroyPath,
 
   -- * Path queries
-  format, 
-  datatype, 
+  pathFormat, 
+  pathDatatype, 
   pathScale, 
-  bias, 
+  pathBias, 
+
   numSegments, 
   numCoords,
 
@@ -64,6 +61,11 @@
   -- * Transforming a path
   transformPath,
   
+  -- * Querying the bounds of a path 
+  BoundingBox(..),
+  pathBounds, 
+  pathTransformedBounds,
+  
   -- * Interpolating between paths
   interpolatePath,
   
@@ -88,8 +90,10 @@
   drawPath,
   fillPath,
   strokePath,
-  fillStrokePath
+  fillStrokePath,
 
+  marshalPathSegment
+
 ) where
 
 import Graphics.Rendering.OpenVG.VG.Parameters
@@ -105,11 +109,13 @@
     GettableStateVar, makeGettableStateVar,
     ( $= ) ) 
 
-import Control.Applicative
 import Control.Monad
 import Data.Int ( Int8, Int16, Int32 )
+
+import Foreign.Marshal.Alloc ( alloca )
 import Foreign.Marshal.Array ( newArray )
-import Foreign.Storable ( Storable )
+import Foreign.Ptr ( Ptr )
+import Foreign.Storable ( Storable, peek )
 
 --------------------------------------------------------------------------------
 -- Datatypes
@@ -132,6 +138,9 @@
    | Relative
    deriving ( Eq, Ord, Show )
 
+-- | 'PathSegment' corresponds to the OpenVG enumeration 
+-- @VGPathSegment@.     
+--
 data PathSegment = 
      ClosePath
    | MoveTo 
@@ -148,8 +157,9 @@
    | LCWArcTo
    deriving ( Eq, Ord, Show )
 
--- | 'PathCommand' corresponds to the OpenVG enumeration @VGPathCommand@,
--- but includes ClosePath aka @VG_CLOSE_PATH@.      
+-- | 'PathCommand' corresponds to the OpenVG enumeration 
+-- @VGPathCommand@.     
+--
 data PathCommand = 
      MoveToAbs
    | MoveToRel
@@ -200,18 +210,15 @@
    | CapabilityAll
    deriving ( Eq, Ord, Show )
 
+data PathProperties 
+     = PathProperties PathDatatype VGfloat VGfloat VGint VGint [PathCapabilities]
+  deriving (Eq,Ord) 
 
+
 -- | @withPath@ - create a path, run an action on it, destroy the path.
-withPath :: PathDatatype 
-         -> VGfloat 
-         -> VGfloat
-         -> VGint 
-         -> VGint 
-         -> [PathCapabilities]
-         -> (VGPath -> IO a) 
-         -> IO a
-withPath typ scl bi sch cch cs action = do
-    path  <- createPath typ scl bi sch cch cs
+withPath :: PathProperties -> (VGPath -> IO a) -> IO a
+withPath props action = do
+    path  <- createPath props
     ans   <- action path
     destroyPath path
     return ans
@@ -220,14 +227,9 @@
 -- | @createPath@ - corresponds to the OpenVG function @vgCreatePath@.
 -- @createPath@ can only create paths in the standard format 
 -- (VG_PATH_FORMAT_STANDARD), extensions are not supported.   
-createPath :: PathDatatype 
-           -> VGfloat 
-           -> VGfloat
-           -> VGint 
-           -> VGint 
-           -> [PathCapabilities] 
-           -> IO VGPath
-createPath typ scl bi sch cch cs = 
+--
+createPath :: PathProperties -> IO VGPath
+createPath (PathProperties typ scl bi sch cch cs) = 
     vgCreatePath fmt (marshalPathDatatype typ) scl bi sch cch caps
   where
     -- Other paths formats maybe defined as extensions, for the present
@@ -248,23 +250,27 @@
 --------------------------------------------------------------------------------
 --  Path queries
   
--- | @format@ - get the path format. Currently the only supported 
--- format is @VG_PATH_FORMAT_STANDARD@ - 0. 
-format :: VGPath -> GettableStateVar VGint
-format = makeGettableStateVar . flip getParameteri vg_PATH_FORMAT
+-- | @pathFormat@ - get the path format. Currently the only supported 
+-- format is @VG_PATH_FORMAT_STANDARD@ - 0.
+--
+pathFormat :: VGPath -> GettableStateVar VGint
+pathFormat = makeGettableStateVar . flip getParameteri vg_PATH_FORMAT
 
--- | @datatype@ - get the PathDatatype.
-datatype :: VGPath -> GettableStateVar PathDatatype
-datatype = makeGettableStateVar . liftM (unmarshalPathDatatype . fromIntegral)  
-                                . (getParameteri `flip` vg_PATH_DATATYPE)
+-- | @pathDatatype@ - get the PathDatatype.
+--
+pathDatatype :: VGPath -> GettableStateVar PathDatatype
+pathDatatype = makeGettableStateVar . liftM (unmarshalPathDatatype . fromIntegral)  
+                                    . (getParameteri `flip` vg_PATH_DATATYPE)
 
 -- | @pathScale@ - get the scaling factor of the path.    
+--
 pathScale :: VGPath -> GettableStateVar VGfloat
 pathScale = makeGettableStateVar . flip getParameterf vg_PATH_SCALE
 
--- | @bias@ - get the bias factor of the path. 
-bias :: VGPath -> GettableStateVar VGfloat
-bias = makeGettableStateVar . flip getParameterf vg_PATH_BIAS
+-- | @pathBias@ - get the bias factor of the path. 
+--
+pathBias :: VGPath -> GettableStateVar VGfloat
+pathBias = makeGettableStateVar . flip getParameterf vg_PATH_BIAS
 
 -- | @numSegments@ - get the number of segments stored in the path.     
 numSegments :: VGPath -> GettableStateVar VGint 
@@ -281,8 +287,8 @@
 -- | @getPathCapabilities@ corresponds to the OpenVG 
 -- function @vgGetPathCapabilities@. 
 getPathCapabilities :: VGPath -> IO [PathCapabilities]
-getPathCapabilities h = 
-    unbits32 unmarshalPathCapabilities <$> vgGetPathCapabilities h
+getPathCapabilities = 
+    liftM (unbits32 unmarshalPathCapabilities) . vgGetPathCapabilities
     
 -- | @removePathCapabilities@ corresponds to the OpenVG 
 -- function @vgRemovePathCapabilities@.  
@@ -309,21 +315,9 @@
 instance StorablePathData Int32
 instance StorablePathData VGfloat
 
-data PathData = S_8     Int8
-              | S_16    Int16
-              | S_32    Int32
-              | F_float Float
-  deriving (Eq,Ord,Show)
-
-{-
--- final ptr is @const void * pathData@ 
-
-appendPathData :: VGPath -> VGint -> Ptr VGubyte -> Ptr a -> IO ()
-appendPathData = vgAppendPathData
--}
-
+-- TODO is this implementation valid?
 
--- | @appendPathData@ - TODO is this implementation valid?
+-- | @appendPathData@ 
 appendPathData :: StorablePathData a => VGPath -> [PathCommand] -> [a] -> IO ()
 appendPathData h cs ds = do 
     cmd_arr <- newArray (map (fromIntegral . marshalPathCommand) cs)
@@ -350,15 +344,49 @@
 --------------------------------------------------------------------------------
 -- Querying the bounding box of a path
 
--- pathBounds __ TODO 
-                 
--- pathTransformedBounds __ TODO 
+data BoundingBox = 
+      BoundingBox { 
+          min_x     :: VGfloat, 
+          min_y     :: VGfloat,
+          width_bb  :: VGfloat,
+          height_bb :: VGfloat
+        }
+  deriving (Eq,Ord,Show)
 
+
+alloca4 :: Storable a => (Ptr a -> Ptr a -> Ptr a -> Ptr a -> IO b) -> IO b
+alloca4 f = alloca $ \ca ->
+              alloca $ \cb -> 
+                alloca $ \cc ->
+                  alloca $ \cd -> f ca cb cc cd
+
+
+
+pathBounds :: VGPath -> IO BoundingBox
+pathBounds path = alloca4 $ \px py pw ph -> do
+    vgPathBounds path px py pw ph
+    x <- peek px
+    y <- peek py
+    w <- peek pw
+    h <- peek ph
+    return $ BoundingBox x y w h      
+
+
+pathTransformedBounds :: VGPath -> IO BoundingBox
+pathTransformedBounds path = alloca4 $ \px py pw ph -> do
+    vgPathTransformedBounds path px py pw ph
+    x <- peek px
+    y <- peek py
+    w <- peek pw
+    h <- peek ph
+    return $ BoundingBox x y w h      
+
+
 --------------------------------------------------------------------------------
 -- Interpolating between paths
 interpolatePath :: VGPath -> VGPath -> VGPath -> VGfloat -> IO Bool
 interpolatePath dst start end amount =
-    unmarshalBool <$> vgInterpolatePath dst start end amount
+    liftM unmarshalBool $ vgInterpolatePath dst start end amount
   
         
 --------------------------------------------------------------------------------
diff --git a/src/Graphics/Rendering/OpenVG/VG/RenderingQuality.hs b/src/Graphics/Rendering/OpenVG/VG/RenderingQuality.hs
--- a/src/Graphics/Rendering/OpenVG/VG/RenderingQuality.hs
+++ b/src/Graphics/Rendering/OpenVG/VG/RenderingQuality.hs
@@ -3,16 +3,18 @@
 --------------------------------------------------------------------------------
 -- |
 -- Module      :  Graphics.Rendering.OpenVG.VG.RenderingQuality
--- Copyright   :  (c) Stephen Tetley 2008, 2009
+-- Copyright   :  (c) Stephen Tetley 2008-2010
 -- License     :  BSD3
 --
 -- Maintainer  :  Stephen Tetley <stephen.tetley@gmail.com>
 -- Stability   :  unstable
 -- Portability :  GHC
 --
--- This module corresponds to section 6 (Rendering Quality and Antialiasing) 
--- of the OpenVG 1.0.1 specs.
+-- This module corresponds to section 6 (Rendering Quality and 
+-- Antialiasing) of the OpenVG 1.0.1 specs.
 --
+-- Acknowledgement - the matrix code is derived from Sven 
+-- Panne\'s HOpenGL.
 --
 --------------------------------------------------------------------------------
 
@@ -27,12 +29,17 @@
   pixelLayout,
   
   -- * Matrix manipulation
+  VGmatrix,
+  withNewMatrix,
+  withMatrix,
+  newMatrix,
+  getMatrixComponents,
+
   MatrixMode(..),
   matrixMode, 
   
   loadIdentity,
-  loadMatrix,
-  getMatrix,
+  matrix,
   multMatrix,
   translate, 
   scale, 
@@ -49,7 +56,10 @@
 import Data.StateVar (
     StateVar(), makeStateVar, SettableStateVar, makeSettableStateVar )   
 
-import Control.Applicative
+import Control.Monad
+import Foreign.ForeignPtr ( 
+    ForeignPtr, withForeignPtr, mallocForeignPtrArray )
+import Foreign.Marshal.Array ( peekArray, pokeArray )
 import Foreign.Ptr ( Ptr )   
 
 
@@ -99,7 +109,8 @@
 pixelLayout = makeStateVar getPixelLayout setPixelLayout
   where
     getPixelLayout :: IO PixelLayout
-    getPixelLayout = unmarshalPixelLayout . fromIntegral <$> geti ScreenLayout
+    getPixelLayout = liftM (unmarshalPixelLayout . fromIntegral) 
+                           (geti ScreenLayout)
         
     setPixelLayout :: PixelLayout -> IO ()  
     setPixelLayout = seti ScreenLayout . fromIntegral . marshalPixelLayout
@@ -107,6 +118,62 @@
 --------------------------------------------------------------------------------
 -- Matrix manipulation
 
+-- NOTE - VGmatrix is simpler than the corresponding GLmatrix.
+-- Firstly VGmatrix only needs to store Floats (GLmatrix has to 
+-- store Floats or Doubles). Secondly VG matrices are always 
+-- stored in the same order (GL matrices can be row-major or
+-- column-major).
+
+
+-- Represent a 3x3 matrix.
+--
+-- > { sx, shy, w0, shx, sy, w1, tx, ty, w2 }
+--
+-- > | sx  shx tx  |
+-- > | shy sy  ty  |
+-- > | w0  w1  w2  |
+--
+newtype VGmatrix = VGmatrix (ForeignPtr VGfloat)
+  deriving (Eq,Ord,Show)
+
+-- |  Create a new matrix (containing undefined elements)
+-- and call the action to fill it with 3x3 elements.
+--
+-- (See HOpenGL\'s @withNewMatrix@).
+--
+withNewMatrix :: (Ptr VGfloat -> IO ()) -> IO VGmatrix
+withNewMatrix f = do
+    fp <- mallocForeignPtrArray 9
+    withForeignPtr fp f
+    return $ VGmatrix fp
+
+-- | Call the action with the given matrix. 
+-- /Note:/ The action is /not/ allowed to modify the matrix 
+-- elements!
+-- 
+-- (See HOpenGL\'s @withMatrix@).
+--
+withMatrix :: VGmatrix -> (Ptr VGfloat -> IO a) -> IO a
+withMatrix (VGmatrix fp) f = withForeignPtr fp f
+
+-- | Create a new matrix (as a foreign pointer) from the supplied
+-- list of components. The list should have 9 elements and be in
+-- the form:
+--
+-- > [ sx, shy, w0, shx, sy, w1, tx, ty, w2 ]
+--
+newMatrix :: [VGfloat] -> IO VGmatrix
+newMatrix components = withNewMatrix $ flip pokeArray (take 9 components)
+
+
+-- | Extract the components from a matrix.
+--
+getMatrixComponents :: VGmatrix -> IO [VGfloat]
+getMatrixComponents mat = withMatrix mat $ \p -> peekArray 9 p
+
+
+
+
 -- | 'MatrixMode' enumerates the manipulable matrices.  
 data MatrixMode =
      PathUserToSurface
@@ -124,6 +191,7 @@
 matrixMode = makeSettableStateVar $  
     seti MatrixMode . fromIntegral . marshalMatrixMode
 
+
 -- | Set the current matrix to the identity matrix.
 --
 -- 'loadIdentity' corresponds to the OpenVG function 
@@ -132,39 +200,37 @@
 loadIdentity :: IO ()
 loadIdentity = vgLoadIdentity
 
--- NOTE
--- See Graphics.Rendering.OpenGL.GL.CoordTrans
+-- | Query and set the current matrix.
+-- 
+-- 'matrix' is a read-write state variable corresponding to 
+-- OpenVG operations @vgGetMatrix@ (query) and vgLoadMatrix (set). 
+--
+matrix :: StateVar VGmatrix
+matrix = makeStateVar getMatrix loadMatrix
 
 
+
+
 -- | Set the current matrix to the supplied matrix.
 --
 -- 'loadMatrix' corresponds to the OpenVG function @vgLoadMatrix@.
 -- 
--- \*\* Note - this function has an unfortunate type and should
--- be wrapped. \*\* 
---
-loadMatrix :: Ptr VGfloat -> IO ()
-loadMatrix = vgLoadMatrix
+loadMatrix :: VGmatrix -> IO ()
+loadMatrix mat = withMatrix mat vgLoadMatrix
 
 -- | Get the current matrix.
 --
 -- 'getMatrix' corresponds to the OpenVG function @vgGetMatrix@.
--- 
--- \*\* Note - this function has an unfortunate type and should
--- be wrapped. \*\* 
 --
-getMatrix :: IO (Ptr VGfloat)
-getMatrix = vgGetMatrix
+getMatrix :: IO VGmatrix
+getMatrix = withNewMatrix vgGetMatrix
 
 -- | Multiply the current matrix by the supplied matrix.
 -- 
 -- 'multMatrix' corresponds to the OpenVG function @vgMultMatrix@.
--- 
--- \*\* Note - this function has an unfortunate type and should
--- be wrapped. \*\* 
 --
-multMatrix :: Ptr VGfloat -> IO ()
-multMatrix = vgMultMatrix
+multMatrix :: VGmatrix -> IO ()
+multMatrix mat = withMatrix mat vgMultMatrix
 
 -- | Apply a translation to the current matrix.
 --
diff --git a/src/Graphics/Rendering/OpenVG/VG/Scissoring.hs b/src/Graphics/Rendering/OpenVG/VG/Scissoring.hs
--- a/src/Graphics/Rendering/OpenVG/VG/Scissoring.hs
+++ b/src/Graphics/Rendering/OpenVG/VG/Scissoring.hs
@@ -3,7 +3,7 @@
 --------------------------------------------------------------------------------
 -- |
 -- Module      :  Graphics.Rendering.OpenVG.VG.Scissoring
--- Copyright   :  (c) Stephen Tetley 2008, 2009
+-- Copyright   :  (c) Stephen Tetley 2008-2010
 -- License     :  BSD3
 --
 -- Maintainer  :  Stephen Tetley <stephen.tetley@gmail.com>
diff --git a/src/Graphics/Rendering/OpenVG/VG/ShivaExtensions.hs b/src/Graphics/Rendering/OpenVG/VG/ShivaExtensions.hs
--- a/src/Graphics/Rendering/OpenVG/VG/ShivaExtensions.hs
+++ b/src/Graphics/Rendering/OpenVG/VG/ShivaExtensions.hs
@@ -3,7 +3,7 @@
 --------------------------------------------------------------------------------
 -- |
 -- Module      :  Graphics.Rendering.OpenVG.VG.ShivaExtensions
--- Copyright   :  (c) Stephen Tetley 2008, 2009
+-- Copyright   :  (c) Stephen Tetley 2008-2010
 -- License     :  BSD3
 --
 -- Maintainer  :  Stephen Tetley <stephen.tetley@gmail.com>
diff --git a/src/Graphics/Rendering/OpenVG/VG/Utils.hs b/src/Graphics/Rendering/OpenVG/VG/Utils.hs
--- a/src/Graphics/Rendering/OpenVG/VG/Utils.hs
+++ b/src/Graphics/Rendering/OpenVG/VG/Utils.hs
@@ -3,7 +3,7 @@
 --------------------------------------------------------------------------------
 -- |
 -- Module      :  Graphics.Rendering.OpenVG.VG.Utils
--- Copyright   :  (c) Stephen Tetley 2008, 2009
+-- Copyright   :  (c) Stephen Tetley 2008-2010
 -- License     :  BSD3
 --
 -- Maintainer  :  Stephen Tetley <stephen.tetley@gmail.com>
diff --git a/src/Graphics/Rendering/OpenVG/VGU.hs b/src/Graphics/Rendering/OpenVG/VGU.hs
--- a/src/Graphics/Rendering/OpenVG/VGU.hs
+++ b/src/Graphics/Rendering/OpenVG/VGU.hs
@@ -3,7 +3,7 @@
 --------------------------------------------------------------------------------
 -- |
 -- Module      :  Graphics.Rendering.OpenVG.VGU
--- Copyright   :  (c) Stephen Tetley 2008, 2009
+-- Copyright   :  (c) Stephen Tetley 2008-2010
 -- License     :  BSD3
 --
 -- Maintainer  :  Stephen Tetley <stephen.tetley@gmail.com>
diff --git a/src/Graphics/Rendering/OpenVG/VGU/ErrorsInternal.hs b/src/Graphics/Rendering/OpenVG/VGU/ErrorsInternal.hs
--- a/src/Graphics/Rendering/OpenVG/VGU/ErrorsInternal.hs
+++ b/src/Graphics/Rendering/OpenVG/VGU/ErrorsInternal.hs
@@ -3,7 +3,7 @@
 --------------------------------------------------------------------------------
 -- |
 -- Module      :  Graphics.Rendering.OpenVG.VG.ErrorsInternal
--- Copyright   :  (c) Stephen Tetley 2008, 2009
+-- Copyright   :  (c) Stephen Tetley 2008-2010
 -- License     :  BSD3
 --
 -- Maintainer  :  Stephen Tetley <stephen.tetley@gmail.com>
diff --git a/src/Graphics/Rendering/OpenVG/VGU/VGU.hs b/src/Graphics/Rendering/OpenVG/VGU/VGU.hs
--- a/src/Graphics/Rendering/OpenVG/VGU/VGU.hs
+++ b/src/Graphics/Rendering/OpenVG/VGU/VGU.hs
@@ -3,7 +3,7 @@
 --------------------------------------------------------------------------------
 -- |
 -- Module      :  Graphics.Rendering.OpenVG.VGU.VGU
--- Copyright   :  (c) Stephen Tetley 2008, 2009
+-- Copyright   :  (c) Stephen Tetley 2008-2010
 -- License     :  BSD3
 --
 -- Maintainer  :  Stephen Tetley <stephen.tetley@gmail.com>