/usr/share/doc/libhugs-glut-bundled/examples/GLUT/RedBook/BezCurve.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 | {-
BezCurve.hs (adapted from bezcurve.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 draw a Bezier curve.
-}
import System.Exit ( exitWith, ExitCode(ExitSuccess) )
import Graphics.UI.GLUT
ctrlPoints :: [Vertex3 GLfloat]
ctrlPoints = [ Vertex3 (-4)(-4) 0, Vertex3 (-2) 4 0,
Vertex3 2 (-4) 0, Vertex3 4 4 0 ]
myInit :: IO ()
myInit = do
clearColor $= Color4 0 0 0 0
shadeModel $= Flat
m <- newMap1 (0, 1) ctrlPoints
map1 $= Just (m :: GLmap1 Vertex3 GLfloat)
display :: DisplayCallback
display = do
clear [ ColorBuffer ]
-- resolve overloading, not needed in "real" programs
let color3f = color :: Color3 GLfloat -> IO ()
color3f (Color3 1 1 1)
renderPrimitive LineStrip $
mapM_ evalCoord1 [ i/30.0 :: GLfloat | i <- [0..30] ]
-- The following code displays the control points as dots.
pointSize $= 5
color3f (Color3 1 1 0)
renderPrimitive Points $
mapM_ vertex ctrlPoints
flush
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 (-5.0) 5.0 (-5.0*hf/wf) (5.0*hf/wf) (-5.0) 5.0
else ortho (-5.0*wf/hf) (5.0*wf/hf) (-5.0) 5.0 (-5.0) 5.0
matrixMode $= Modelview 0
loadIdentity
keyboard :: KeyboardMouseCallback
keyboard (Char '\27') Down _ _ = exitWith ExitSuccess
keyboard _ _ _ _ = return ()
main :: IO ()
main = do
(progName, _args) <- getArgsAndInitialize
initialDisplayMode $= [ SingleBuffered, RGBMode ]
initialWindowSize $= Size 500 500
initialWindowPosition $= Position 100 100
createWindow progName
myInit
displayCallback $= display
reshapeCallback $= Just reshape
keyboardMouseCallback $= Just keyboard
mainLoop
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