module ShowImage
    (showImage)
where

import           ImageTypes

-- ----------------------------------------

showImage       :: Bool -> Image -> String
showImage bin (Image (Geo w h) at)
    = imgType ++ imgGeo ++ "255\n" ++ imgData
    where
    imgGeo      = show w ++ " " ++ show h ++ "\n# Haskell PPM Tools\n"

    imgType
        | bin           = "P5\n"
        | otherwise     = "P2\n"

    imgData
        = pixToChar . pixToList $ at

    pixToChar
        | bin           = map toEnum
        | otherwise     = concatMap ((++ "\n") . show)

    pixToList f
        = [ toPix (f x y) | y <- [0..h-1], x <- [0..w-1] ]
        where
        toPix   :: Lightness -> Int
        toPix c = floor (c * 256.0) `min` 255 `max` 0

-- ----------------------------------------