/usr/share/doc/libghc-glut-doc/examples/BOGLGP/Chapter03/Points.hs is in libghc-glut-doc 2.7.0.12-1build5.
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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 | {-
Points.hs (adapted from Points which is (c) 2004 Astle/Hawkins)
Copyright (c) Sven Panne 2004-2005 <svenpanne@gmail.com>
This file is part of HOpenGL and distributed under a BSD-style license
See the file libraries/GLUT/LICENSE
-}
import Control.Monad ( when, unless, zipWithM_ )
import Data.Maybe ( isJust )
import Graphics.UI.GLUT hiding ( initialize )
import System.Console.GetOpt
import System.Environment ( getProgName )
import System.Exit ( exitWith, ExitCode(..) )
import System.IO ( hPutStr, stderr )
--------------------------------------------------------------------------------
-- Setup GLUT and OpenGL, drop into the event loop.
--------------------------------------------------------------------------------
main :: IO ()
main = do
-- Setup the basic GLUT stuff
(_, args) <- getArgsAndInitialize
opts <- parseOptions args
initialDisplayMode $= [ DoubleBuffered, RGBMode, WithDepthBuffer ]
(if useFullscreen opts then fullscreenMode else windowedMode) opts
initialize
-- Register the event callback functions
displayCallback $= do render; swapBuffers
reshapeCallback $= Just setupProjection
keyboardMouseCallback $= Just keyboardMouseHandler
-- No need for an idle callback here, this would just hog the CPU
-- without any visible effect
-- At this point, control is relinquished to the GLUT event handler.
-- Control is returned as events occur, via the callback functions.
mainLoop
fullscreenMode :: Options -> IO ()
fullscreenMode opts = do
let addCapability c = maybe id (\x -> (Where' c IsEqualTo x :))
gameModeCapabilities $=
(addCapability GameModeWidth (Just (windowWidth opts)) .
addCapability GameModeHeight (Just (windowHeight opts)) .
addCapability GameModeBitsPerPlane (bpp opts) .
addCapability GameModeRefreshRate (refreshRate opts)) []
_ <- enterGameMode
maybeWin <- get currentWindow
if isJust maybeWin
then cursor $= None
else do
hPutStr stderr "Could not enter fullscreen mode, using windowed mode\n"
windowedMode (opts { useFullscreen = False } )
windowedMode :: Options -> IO ()
windowedMode opts = do
initialWindowSize $=
Size (fromIntegral (windowWidth opts)) (fromIntegral (windowHeight opts))
_ <- createWindow "BOGLGP - Chapter 3 - Points"
return ()
--------------------------------------------------------------------------------
-- Option handling
--------------------------------------------------------------------------------
data Options = Options {
useFullscreen :: Bool,
windowWidth :: Int,
windowHeight :: Int,
bpp :: Maybe Int,
refreshRate :: Maybe Int
}
startOpt :: Options
startOpt = Options {
useFullscreen = False,
windowWidth = 800,
windowHeight = 600,
bpp = Nothing,
refreshRate = Nothing
}
options :: [OptDescr (Options -> IO Options)]
options = [
Option ['f'] ["fullscreen"]
(NoArg (\opt -> return opt { useFullscreen = True }))
"use fullscreen mode if possible",
Option ['w'] ["width"]
(ReqArg (\arg opt -> do w <- readInt "WIDTH" arg
return opt { windowWidth = w })
"WIDTH")
"use window width WIDTH",
Option ['h'] ["height"]
(ReqArg (\arg opt -> do h <- readInt "HEIGHT" arg
return opt { windowHeight = h })
"HEIGHT")
"use window height HEIGHT",
Option ['b'] ["bpp"]
(ReqArg (\arg opt -> do b <- readInt "BPP" arg
return opt { bpp = Just b })
"BPP")
"use BPP bits per plane (ignored in windowed mode)",
Option ['r'] ["refresh-rate"]
(ReqArg (\arg opt -> do r <- readInt "HZ" arg
return opt { refreshRate = Just r })
"HZ")
"use refresh rate HZ (ignored in windowed mode)",
Option ['?'] ["help"]
(NoArg (\_ -> do usage >>= putStr
safeExitWith ExitSuccess))
"show help" ]
readInt :: String -> String -> IO Int
readInt name arg =
case reads arg of
((x,[]) : _) -> return x
_ -> dieWith ["Can't parse " ++ name ++ " argument '" ++ arg ++ "'\n"]
usage :: IO String
usage = do
progName <- getProgName
return $ usageInfo ("Usage: " ++ progName ++ " [OPTION...]") options
parseOptions :: [String] -> IO Options
parseOptions args = do
let (optsActions, nonOptions, errs) = getOpt Permute options args
unless (null nonOptions && null errs) (dieWith errs)
foldl (>>=) (return startOpt) optsActions
dieWith :: [String] -> IO a
dieWith errs = do
u <- usage
mapM_ (hPutStr stderr) (errs ++ [u])
safeExitWith (ExitFailure 1)
--------------------------------------------------------------------------------
-- Handle mouse and keyboard events. For this simple demo, just exit when
-- ESCAPE is pressed.
--------------------------------------------------------------------------------
keyboardMouseHandler :: KeyboardMouseCallback
keyboardMouseHandler (Char '\27') Down _ _ = safeExitWith ExitSuccess
keyboardMouseHandler _ _ _ _ = return ()
safeExitWith :: ExitCode -> IO a
safeExitWith code = do
gma <- get gameModeActive
when gma leaveGameMode
exitWith code
--------------------------------------------------------------------------------
-- Do one time setup, i.e. set the clear color.
--------------------------------------------------------------------------------
initialize :: IO ()
initialize = clearColor $= Color4 0 0 0 0
--------------------------------------------------------------------------------
-- Reset the viewport for window changes.
--------------------------------------------------------------------------------
setupProjection :: ReshapeCallback
setupProjection (Size width height) = do
-- don't want a divide by zero
let h = max 1 height
-- reset the viewport to new dimensions
viewport $= (Position 0 0, Size width h)
-- set projection matrix as the current matrix
matrixMode $= Projection
-- reset projection matrix
loadIdentity
-- calculate aspect ratio of window
perspective 52 (fromIntegral width / fromIntegral h) 1 1000
-- set modelview matrix
matrixMode $= Modelview 0
-- reset modelview matrix
loadIdentity
--------------------------------------------------------------------------------
-- Clear and redraw the scene.
--------------------------------------------------------------------------------
render :: DisplayCallback
render = do
-- clear screen and depth buffer
clear [ ColorBuffer, DepthBuffer ]
loadIdentity
lookAt (Vertex3 0 6 0.1) (Vertex3 0 0 0) (Vector3 0 1 0)
-- draw a line of points of increasing size
zipWithM_ (\ps point -> do
-- set the point size
pointSize $= ps
-- draw the point
renderPrimitive Points $
vertex (Vertex3 point 0 0))
[ 0.5 .. ]
[ -4, -3.5 .. 4.5 :: GLfloat ]
|