/usr/share/doc/libhugs-glut-bundled/examples/GLUT/RedBook/BezSurf.hs is in libhugs-glut-bundled 98.200609.21-5.3.
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 | {-
BezSurf.hs (adapted from bezsurf.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 renders a wireframe Bezier surface, using two-dimensional
evaluators.
-}
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) ]]
-- Hey mom, look, it's C! ;-)
for :: GLfloat -> GLfloat -> (GLfloat -> IO ()) -> IO ()
for s e f = mapM_ f [ i | i <- [ s, if s <= e then s + 1 else s - 1 .. e ] ]
display :: DisplayCallback
display = do
clear [ ColorBuffer, DepthBuffer ]
color (Color3 1 1 1 :: Color3 GLfloat)
preservingMatrix $ do
rotate (85 :: GLfloat) (Vector3 1 1 1)
for 0 8 $ \j -> do
renderPrimitive LineStrip $ do
for 0 30 $ \i -> evalCoord2 (i/30, j/ 8)
renderPrimitive LineStrip $ do
for 0 30 $ \i -> evalCoord2 (j/ 8, i/30)
flush
myInit :: IO ()
myInit = do
clearColor $= Color4 0 0 0 0
m <- newMap2 (0, 1) (0, 1) ctrlPoints
map2 $= Just (m :: GLmap2 Vertex3 GLfloat)
mapGrid2 $= ((20, (0, 1)), (20, (0, 1 :: GLfloat)))
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
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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