{-# LANGUAGE ForeignFunctionInterface #-}

module Phi.Bindings.Cairo ( createXCBSurface
                          ) where

import Control.Monad

import Data.Int
import Data.Word

import Foreign.C.Types
import Foreign.ForeignPtr
import Foreign.Marshal.Alloc
import Foreign.Marshal.Utils
import Foreign.Ptr
import Foreign.Storable

import Graphics.Rendering.Cairo.Types
import Graphics.XHB (toValue)
import Graphics.XHB.Connection.XCB
import Graphics.XHB.Gen.Xproto (DRAWABLE, VISUALTYPE(..))


#include <cairo-xcb.h>


foreign import ccall "cairo-xlib.h cairo_xcb_surface_create"
  cairo_xcb_surface_create :: Ptr XCBConnection -> DRAWABLE -> Ptr VISUALTYPE -> CInt -> CInt -> IO (Ptr Surface)

instance Storable VISUALTYPE where
  sizeOf _ = (#size xcb_visualtype_t)
  alignment _ = alignment (undefined :: CInt)
  
  peek _ = error "VISUALTYPE: peek not implemented"
  
  poke vt (MkVISUALTYPE visual_id _class bits_per_rgb_value colormap_entries red_mask green_mask blue_mask) = do
    (#poke xcb_visualtype_t, visual_id) vt visual_id
    (#poke xcb_visualtype_t, _class) vt (toValue _class :: Word8)
    (#poke xcb_visualtype_t, bits_per_rgb_value) vt bits_per_rgb_value
    (#poke xcb_visualtype_t, colormap_entries) vt colormap_entries
    (#poke xcb_visualtype_t, red_mask) vt red_mask
    (#poke xcb_visualtype_t, green_mask) vt green_mask
    (#poke xcb_visualtype_t, blue_mask) vt blue_mask

createXCBSurface :: Connection -> DRAWABLE -> VISUALTYPE -> CInt -> CInt -> IO Surface
createXCBSurface conn drawable visual width height =
  with visual $ \visualptr -> withConnection conn $ \connptr -> do
    surfacePtr <- cairo_xcb_surface_create connptr drawable visualptr width height
    surface <- mkSurface surfacePtr
    manageSurface surface
    return surface