[Haskell-cafe] OpenGL: No instance for Random GLfloat

[Mark Spezzano]

Hi Haskellers,

I'm trying to generate a random vertex in OpenGL as follows.

genPosition :: IO (Vertex3 GLfloat)
genPosition = do x <- getStdRandom $ randomR (-1.6,1.6)
                               y <- getStdRandom $ randomR (-1.0,1.0)
                              return (Vertex3 x y (-1))

Unfortunately the compiler complains about me having to implement an instance of Random for  GLfloat.

How do I do this (or avoid having to do this)?

Cheers,

Mark