/usr/share/doc/libhugs-glut-bundled/examples/GLUT/RedBook/ColorMatrix.hs is in libhugs-glut-bundled 98.200609.21-5.3ubuntu1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 | {-
ColorMatrix.hs (adapted from colormatrix.c which is (c) Silicon Graphics, Inc.)
Copyright (c) Sven Panne 2002-2005 <sven.panne@aedion.de>
This file is part of HOpenGL and distributed under a BSD-style license
See the file libraries/GLUT/LICENSE
This program uses the color matrix to exchange the color channels of an image.
Red -> Green
Green -> Blue
Blue -> Red
-}
import System.Exit ( exitWith, ExitCode(ExitSuccess) )
import Graphics.UI.GLUT
import ReadImage
myInit :: IO ()
myInit = do
m <- newMatrix ColumnMajor [ 0, 1, 0, 0,
0, 0, 1, 0,
1, 0, 0, 0,
0, 0, 0, 1 ]
rowAlignment Unpack $= 1
clearColor $= Color4 0 0 0 0
matrixMode $= Color
matrix Nothing $= (m :: GLmatrix GLfloat)
matrixMode $= Modelview 0
display :: Size -> PixelData a -> DisplayCallback
display size pixels = do
clear [ ColorBuffer ]
-- resolve overloading, not needed in "real" programs
let rasterPos2i = rasterPos :: Vertex2 GLint -> IO ()
rasterPos2i (Vertex2 1 1)
drawPixels size pixels
flush
reshape :: ReshapeCallback
reshape size@(Size w h) = do
viewport $= (Position 0 0, size)
matrixMode $= Projection
loadIdentity
ortho 0 (fromIntegral w) 0 (fromIntegral h) (-1) 1
matrixMode $= Modelview 0
keyboard :: KeyboardMouseCallback
keyboard (Char '\27') Down _ _ = exitWith ExitSuccess
keyboard _ _ _ _ = return ()
-- Main Loop: Open window with initial window size, title bar, RGBA display
-- mode, and handle input events.
main :: IO ()
main = do
(progName, args) <- getArgsAndInitialize
(size, pixels) <- readImage (if null args then "Data/leeds.bin" else head args)
initialDisplayMode $= [ SingleBuffered, RGBMode ]
initialWindowSize $= size
initialWindowPosition $= Position 100 100
createWindow progName
myInit
reshapeCallback $= Just reshape
keyboardMouseCallback $= Just keyboard
displayCallback $= display size pixels
mainLoop
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