module Examples.Utils.PPM where

import qualified Data.Array.Accelerate as A
import Data.Word


type RGB = (Word8, Word8, Word8)

ppmWrite :: A.Matrix RGB -> FilePath -> IO ()
ppmWrite img fp = do
    let A.Z A.:. h A.:. w = A.arrayShape img
        line y = unwords $ concat [[show r, show g, show b] | x <- [0 .. w - 1], let (r, g, b) = A.indexArray img (A.Z A.:. y A.:. x)]
        contents = unlines $
            ["P3"
            ,show w ++ " " ++ show h
            ,"255"]
            ++ [line y | y <- [0 .. h - 1]]
    writeFile fp contents