Main.hs

module Main where

import Brillo
import System.Environment


-- | Displays uncompressed 24/32 bit BMP images.
main :: IO ()
main =
  do
    args <- getArgs
    case args of
      [fileName] -> run fileName
      _ ->
        putStr $
          unlines
            [ "usage: bitmap <file.bmp>"
            , "  file.bmp should be a 24 or 32-bit uncompressed BMP file"
            ]


run :: FilePath -> IO ()
run fileName =
  do
    picture@(Bitmap bmpData) <-
      loadBMP fileName

    let (width, height) = bitmapSize bmpData
    animate
      (InWindow fileName (width, height) (10, 10))
      black
      (frame width height picture)


frame :: Int -> Int -> Picture -> Float -> Picture
frame width height picture t =
  Color (greyN (abs $ sin (t * 2))) $
    Pictures
      [ rectangleSolid (fromIntegral width) (fromIntegral height)
      , picture
      ]