Question

Here is my source code I’m trying to get to work:

In Main.hs:

import Graphics.Rendering.OpenGL
import Graphics.UI.GLUT
import Bindings
import Data.IORef
main = do
    (progname,_) <- getArgsAndInitialize
    createWindow "Hello World"
    reshapeCallback $= Just reshape
    keyboardMouseCallback $= Just keyboardMouse
    angle <- newIORef 0.0
    displayCallback $= display
    idleCallback $= Just idle
    mouseWheelCallback $= Just mouseWheel
    mainLoop

In Bindings.hs:

module Bindings where
import Graphics.Rendering.OpenGL
import Graphics.UI.GLUT

display :: IO ()
display = return ()

overlayDisplay :: IO ()
overlayDisplay = return ()

visibility :: Visibility -> IO ()
visibility v = return ()

reshape :: Size -> IO ()
reshape s@(Size w h) = do 
    viewport $= (Position 0 0, s)

close :: IO ()
close = return ()

keyboardMouse :: Key -> KeyState -> Modifiers -> Position -> IO ()
keyboardMouse key state modifiers position = return ()

mouseWheel :: WheelNumber -> WheelDirection -> Position -> IO ()
mouseWheel wn wd p = return ()

idle :: IO ()
idle = return ()

It works if I use normal glut32.dll and none of the freeglut extensions in my code, but I want to use the freeglut extensions.

When I use freeglut.dll, rename it to glut32.dll, and put it in the same folder as my .exe, it gives me the error:

main: user error (unknown GLUT entry glutInit)

When I use the normal glut32.dll in the same way I get the error:

main: user error (unknown GLUT entry glutMouseWheelFunc)

Answer 1

You have to use freeglut .lib/.dll from Mingw or compile it yourself.