/usr/share/doc/libghc-glut-doc/examples/RedBook/TextureSurf.hs is in libghc-glut-doc 2.1.2.1-3.
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 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 | {-
TextureSurf.hs (adapted from texturesurf.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 evaluators to generate a curved surface and automatically
generated texture coordinates.
-}
import Data.List ( transpose )
import Foreign ( withArray )
import System.Exit ( exitWith, ExitCode(ExitSuccess) )
import Graphics.UI.GLUT
ctrlPoints :: [[Vertex3 GLfloat]]
ctrlPoints = [
[ Vertex3 (-1.5) (-1.5) 4.0, Vertex3 (-0.5) (-1.5) 2.0,
Vertex3 0.5 (-1.5) (-1.0), Vertex3 1.5 (-1.5) 2.0 ],
[ Vertex3 (-1.5) (-0.5) 1.0, Vertex3 (-0.5) (-0.5) 3.0,
Vertex3 0.5 (-0.5) 0.0, Vertex3 1.5 (-0.5) (-1.0) ],
[ Vertex3 (-1.5) 0.5 4.0, Vertex3 (-0.5) 0.5 0.0,
Vertex3 0.5 0.5 3.0, Vertex3 1.5 0.5 4.0 ],
[ Vertex3 (-1.5) 1.5 (-2.0), Vertex3 (-0.5) 1.5 (-2.0),
Vertex3 0.5 1.5 0.0, Vertex3 1.5 1.5 (-1.0) ]]
texPts :: [[TexCoord2 GLfloat]]
texPts = [
[ TexCoord2 0 0, TexCoord2 0 1 ],
[ TexCoord2 1 0, TexCoord2 1 1 ]]
display :: DisplayCallback
display = do
clear [ ColorBuffer, DepthBuffer ]
color (Color3 1 1 1 :: Color3 GLfloat)
evalMesh2 Fill (0, 20) (0, 20)
flush
imageSize :: TextureSize2D
imageSize = TextureSize2D 64 64
withImage :: (PixelData (Color3 GLubyte) -> IO ()) -> IO ()
withImage act =
withArray [ Color3 (s (sin ti)) (s (cos (2 * tj))) (s (cos (ti + tj))) |
i <- [ 0 .. fromIntegral w - 1 ],
let ti = 2 * pi * i / fromIntegral w,
j <- [ 0 .. fromIntegral h - 1 ],
let tj = 2 * pi * j / fromIntegral h ] $
act . PixelData RGB UnsignedByte
where (TextureSize2D w h) = imageSize
s :: Double -> GLubyte
s x = truncate (127 * (1 + x))
myInit :: IO ()
myInit = do
m <- newMap2 (0, 1) (0, 1) (transpose ctrlPoints)
map2 $= Just (m :: GLmap2 Vertex3 GLfloat)
t <- newMap2 (0, 1) (0, 1) (transpose texPts)
map2 $= Just (t :: GLmap2 TexCoord2 GLfloat)
mapGrid2 $= ((20, (0, 1)), (20, (0, 1 :: GLfloat)))
textureFunction $= Decal
textureWrapMode Texture2D S $= (Repeated, Repeat)
textureWrapMode Texture2D T $= (Repeated, Repeat)
textureFilter Texture2D $= ((Nearest, Nothing), Nearest)
withImage $ texImage2D Nothing NoProxy 0 RGB' imageSize 0
texture Texture2D $= Enabled
depthFunc $= Just Less
shadeModel $= Flat
reshape :: ReshapeCallback
reshape size@(Size w h) = do
viewport $= (Position 0 0, size)
matrixMode $= Projection
loadIdentity
let wf = fromIntegral w
hf = fromIntegral h
if w <= h
then ortho (-4.0) 4.0 (-4.0*hf/wf) (4.0*hf/wf) (-4.0) 4.0
else ortho (-4.0*wf/hf) (4.0*wf/hf) (-4.0) 4.0 (-4.0) 4.0
matrixMode $= Modelview 0
loadIdentity
rotate (85 :: GLfloat) (Vector3 1 1 1)
keyboard :: KeyboardMouseCallback
keyboard (Char '\27') Down _ _ = exitWith ExitSuccess
keyboard _ _ _ _ = return ()
main :: IO ()
main = do
(progName, _args) <- getArgsAndInitialize
initialDisplayMode $= [ SingleBuffered, RGBMode, WithDepthBuffer ]
initialWindowSize $= Size 500 500
initialWindowPosition $= Position 100 100
createWindow progName
myInit
displayCallback $= display
reshapeCallback $= Just reshape
keyboardMouseCallback $= Just keyboard
mainLoop
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