{-# OPTIONS -Wall #-}

--------------------------------------------------------------------------------
-- |
-- Module      :  Graphics.Rendering.OpenVG.VG.RenderingQuality
-- Copyright   :  (c) Stephen Tetley 2008, 2009
-- License     :  BSD3
--
-- Maintainer  :  Stephen Tetley <stephen.tetley@gmail.com>
-- Stability   :  highly unstable
-- Portability :  GHC
--
-- This module corresponds to section 6 (Rendering Quality and Antialiasing) 
-- of the OpenVG 1.0.1 specs.
--
--
--------------------------------------------------------------------------------

module Graphics.Rendering.OpenVG.VG.RenderingQuality (
  
  -- * Rendering quality
  RenderingQuality(..), 
  renderingQuality,
  
  -- * Additional quality settings
  PixelLayout(..), 
  pixelLayout,
  
  -- * Matrix manipulation
  MatrixMode(..),
  matrixMode, 
  
  loadIdentity,
  loadMatrix,
  getMatrix,
  multMatrix,
  translate, 
  scale, 
  shear, 
  rotate
) where

import Graphics.Rendering.OpenVG.VG.BasicTypes ( 
    VGfloat, VGenum )
import Graphics.Rendering.OpenVG.VG.CFunDecls ( 
    vgLoadIdentity, vgLoadMatrix, vgGetMatrix, vgMultMatrix, 
    vgTranslate, vgScale, vgShear, vgRotate
    )
import Graphics.Rendering.OpenVG.VG.Constants (
    vg_RENDERING_QUALITY_NONANTIALIASED, vg_RENDERING_QUALITY_FASTER,
    vg_RENDERING_QUALITY_BETTER,
    --
    vg_PIXEL_LAYOUT_UNKNOWN, 
    vg_PIXEL_LAYOUT_RGB_VERTICAL, vg_PIXEL_LAYOUT_BGR_VERTICAL,
    vg_PIXEL_LAYOUT_RGB_HORIZONTAL, vg_PIXEL_LAYOUT_BGR_HORIZONTAL,
    --
    vg_MATRIX_PATH_USER_TO_SURFACE, vg_MATRIX_IMAGE_USER_TO_SURFACE, 
    vg_MATRIX_FILL_PAINT_TO_USER, vg_MATRIX_STROKE_PAINT_TO_USER, 
    )  
import Graphics.Rendering.OpenVG.VG.Parameters ( 
    ParamType ( MatrixMode, RenderingQuality, ScreenLayout ), 
    seti, geti  )
import Graphics.Rendering.OpenVG.VG.Utils ( 
    Marshal(..), Unmarshal(..), enumValue, unmarshalIntegral )

import Graphics.Rendering.OpenGL.GL.StateVar (
    StateVar(), makeStateVar, SettableStateVar, makeSettableStateVar )   

import Foreign.Ptr ( Ptr )   


--------------------------------------------------------------------------------
-- Rendering quality
                     
-- | @RenderingQuality@ corresponds to the OpenVG 
-- enumeration @VGRenderingQuality@. 
data RenderingQuality = 
     Nonantialiased'
   | Faster'
   | Better'
   deriving ( Eq, Ord, Show )

-- | Set the rendering quality - the default is /Better/.
renderingQuality :: SettableStateVar RenderingQuality  
renderingQuality = makeSettableStateVar $ \mode -> 
    seti RenderingQuality (enumValue mode) 
    
--------------------------------------------------------------------------------
-- Additional quality settings 

-- | @PixelLayout@ corresponds to the OpenVG enumeration @VGPixelLayout@.  
data PixelLayout = 
     Unknown
   | RgbVertical
   | BgrVertical
   | RgbHorizontal
   | BgrHorizontal
   deriving ( Eq, Ord, Show )

-- | @pixelLayout@ - a @StateVar@ to get and set the pixel layout.
pixelLayout :: StateVar PixelLayout
pixelLayout = makeStateVar getPixelLayout setPixelLayout
  where
    getPixelLayout :: IO PixelLayout
    getPixelLayout = do
        a <- geti ScreenLayout 
        return $ unmarshalIntegral a
        
    setPixelLayout :: PixelLayout -> IO ()  
    setPixelLayout a = seti ScreenLayout (enumValue a)  
    
--------------------------------------------------------------------------------
-- Matrix manipulation

-- | @MatrixMode@ corresponds to the OpenVG  enumeration @VGMatrixMode@.  
data MatrixMode =
     PathUserToSurface
   | ImageUserToSurface
   | FillPaintToUser
   | StrokePaintToUser
   deriving ( Eq, Ord, Show )   

-- | Set the matrix mode.
matrixMode :: SettableStateVar MatrixMode  
matrixMode = makeSettableStateVar $ \mode -> 
    seti MatrixMode (enumValue mode) 

-- | @loadIdentity@ corresponds to the OpenVG function @vgLoadIdentity@. 
loadIdentity :: IO ()
loadIdentity = vgLoadIdentity

-- | @loadMatrix@ corresponds to the OpenVG function @vgLoadMatrix@. 
loadMatrix :: Ptr VGfloat -> IO ()
loadMatrix = vgLoadMatrix

-- | @getMatrix@ - TODO.
getMatrix :: IO (Ptr VGfloat)
getMatrix = vgGetMatrix

-- | @multMatrix@ - TODO.
multMatrix :: Ptr VGfloat -> IO ()
multMatrix = vgMultMatrix

-- | @translate@ corresponds to the OpenVG function @vgTranslate@. 
translate :: VGfloat -> VGfloat -> IO ()
translate = vgTranslate

-- | @scale@ corresponds to the OpenVG function @vgScale@. 
scale :: VGfloat -> VGfloat -> IO ()
scale = vgScale

-- | @shear@ corresponds to the OpenVG function @vgShear@.     
shear :: VGfloat -> VGfloat -> IO ()
shear = vgShear

-- | @rotate@ corresponds to the OpenVG function @vgRotate@.     
rotate :: VGfloat -> IO ()
rotate = vgRotate    
    

--------------------------------------------------------------------------------
   
marshalRenderingQuality :: RenderingQuality -> VGenum
marshalRenderingQuality x = case x of
    Nonantialiased' -> vg_RENDERING_QUALITY_NONANTIALIASED  
    Faster' -> vg_RENDERING_QUALITY_FASTER
    Better' -> vg_RENDERING_QUALITY_BETTER

instance Marshal RenderingQuality where marshal = marshalRenderingQuality

marshalPixelLayout :: PixelLayout -> VGenum
marshalPixelLayout x = case x of
    Unknown -> vg_PIXEL_LAYOUT_UNKNOWN
    RgbVertical -> vg_PIXEL_LAYOUT_RGB_VERTICAL
    BgrVertical -> vg_PIXEL_LAYOUT_BGR_VERTICAL
    RgbHorizontal -> vg_PIXEL_LAYOUT_RGB_HORIZONTAL
    BgrHorizontal -> vg_PIXEL_LAYOUT_BGR_HORIZONTAL

instance Marshal PixelLayout where marshal = marshalPixelLayout


unmarshalPixelLayout :: VGenum -> PixelLayout 
unmarshalPixelLayout x
    | x == vg_PIXEL_LAYOUT_UNKNOWN        = Unknown
    | x == vg_PIXEL_LAYOUT_RGB_VERTICAL   = RgbVertical 
    | x == vg_PIXEL_LAYOUT_BGR_VERTICAL   = BgrVertical 
    | x == vg_PIXEL_LAYOUT_RGB_HORIZONTAL = RgbHorizontal 
    | x == vg_PIXEL_LAYOUT_BGR_HORIZONTAL = BgrHorizontal 
    | otherwise = error ("unmarshalPixelLayout: illegal value " ++ show x)
    
instance Unmarshal PixelLayout where unmarshal = unmarshalPixelLayout
    
marshalMatrixMode :: MatrixMode -> VGenum
marshalMatrixMode x = case x of 
    PathUserToSurface -> vg_MATRIX_PATH_USER_TO_SURFACE
    ImageUserToSurface -> vg_MATRIX_IMAGE_USER_TO_SURFACE
    FillPaintToUser -> vg_MATRIX_FILL_PAINT_TO_USER
    StrokePaintToUser -> vg_MATRIX_STROKE_PAINT_TO_USER
    
instance Marshal MatrixMode where marshal = marshalMatrixMode