{-# LANGUAGE ForeignFunctionInterface #-}

-- | 
-- Module     : Mac.QuickDraw
-- Maintainer : Yakov Z <>
-- Stability  : experimental
--
 
module Mac.QuickDraw (
  -- * QuickDraw
  GDHandle,
  PixMap(..),

--TO-DO hide
  PixMapHandle,

  -- ** Hiding and Showing Cursors
  initCursor,

  -- ** Getting the Available Graphics Devices
  getMainDevice,

  -- ** Managing and Offscreen Graphics World's Pixel Image
  getPixBaseAddr,
  lockPixels,

  -- ** Miscellaneous
  getPortPixMap,
  getPixRowBytes  
                     ) where

import Foreign.Ptr
import Foreign.C.Types
import Foreign.Storable

import Mac.Carbon

#include <QuickTime/QuickTime.h>

type GDHandle = Ptr ()

-- | Contains information about the dimensions and contents of a pixel image, as well as 
-- its storage format, depth, resolution, and color usage.
--
-- For an onscreen pixel image, 'baseAddr' is a pointer to the first byte of the image. For optimal performance,
-- this should be multiple of 4. 
--
-- The 'baseAddr' of the 'PixMap' for an /offscreen/ graphics world contains a handle instead of a pointer.
--
-- Your application should never directly access the 'baseAddr' for an /offscreen/ graphics world.
--
-- <http://developer.apple.com/documentation/QuickTime/Reference/QTRef_DataTypes/Reference/reference.html#//apple_ref/doc/c_ref/PixMap>
--
data PixMap = PixMap { baseAddr :: Ptr (),
                       rowBytes :: CShort
                     }
instance Storable PixMap where
    sizeOf _ = #const sizeof(PixMap)
    alignment _ = alignment (undefined :: CInt) -- ???
    peek p = do
      baseAddr' <- (#peek PixMap, baseAddr) p
      rowBytes' <- (#peek PixMap, rowBytes) p
      return PixMap { baseAddr = baseAddr', rowBytes = rowBytes' }

type PixMapPtr = Ptr PixMap
type PixMapHandle = Ptr PixMapPtr

-- | Sets the cursor to the standard arrow and makes the cursor visible.
foreign import ccall unsafe "InitCursor" initCursor :: IO ()

-- | Obtains a handle to the GDevice structure for the main screen.
-- 
-- Deprecated in Mac OS X v10.4
foreign import ccall unsafe "GetMainDevice" getMainDevice :: IO GDHandle

foreign import ccall unsafe "GetPixBaseAddr" getPixBaseAddr :: PixMapHandle -> IO (Ptr ())
foreign import ccall unsafe "LockPixels" lockPixels :: PixMapHandle -> IO Boolean

foreign import ccall unsafe "GetPortPixMap" getPortPixMap :: CGrafPtr -> IO PixMapHandle
foreign import ccall unsafe "GetPixRowBytes" getPixRowBytes :: PixMapHandle -> IO CInt