QPawn.hs

   1 {-# LANGUAGE ForeignFunctionInterface #-}
   2
   3 module Main where
   4
   5 import Foreign
   6 import Foreign.C.Types
   7 import Data.Int
   8
   9 -- | foreign imports
  10 foreign import ccall "qpawn.c init"
  11     c_init :: IO ()
  12
  13 foreign import ccall "qpawn.c quit"
  14     c_quit :: IO ()
  15
  16 foreign import ccall "qpawn.c clear"
  17     c_clear :: IO ()
  18
  19 foreign import ccall "qpawn.c draw"
  20     c_draw :: IO ()
  21
  22 foreign import ccall "qpawn.c pixel"
  23     c_pixel :: CInt -> CInt -> IO ()
  24
  25 foreign import ccall "qpawn.c color"
  26     c_color :: CInt -> CInt -> CInt -> IO ()
  27
  28 foreign import ccall "qpawn.c sleep"
  29     c_sleep :: CInt -> IO ()
  30
  31
  32 -- | actual code
  33 -- hide this one from module?
  34 cint :: (Integral a) => a -> CInt
  35 cint n = (fromIntegral n) :: CInt
  36
  37 color :: Int -> Int -> Int -> IO ()
  38 color r g b = c_color r' g' b'
  39     where (r', g', b') = (cint r, cint g, cint b)
  40
  41 pixel :: Int32 -> Int32 -> IO ()
  42 pixel x y = c_pixel x' y'
  43     where (x', y') = (cint x, cint y)
  44
  45 clear :: IO ()
  46 clear = c_clear
  47
  48 sleep :: Int -> IO ()
  49 sleep = c_sleep . cint
  50
  51 draw :: IO ()
  52 draw = c_draw
  53
  54 main :: IO ()
  55 main = do c_init
  56           color 0 0 0
  57           clear
  58           draw
  59           sleep 2
  60           color 255 255 255
  61           clear
  62           draw
  63           sleep 2
  64           c_quit