[Haskell-beginners] integer to noise function in Haskell

[Florian Gillard]

Got it, the error was coming from me thinking of the C "^" operator as
exponent, instead of bitwise xoring.

On Wed, Apr 22, 2015 at 3:39 PM, Florian Gillard <florian.gillard at gmail.com>
wrote:

> I am trying to implement a basic pelin noise function, but I have some
> problem with the integer to noise function used to generate deterministic
> noise from integer inputs.
>
> the function I am trying to implement is defined there:
> http://libnoise.sourceforge.net/noisegen/index.html#continuousnoise
>
> and my code so far look like this:
>
> noise2d :: (Int32, Int32) -> Double
> noise2d (x, y) =
>     let m = x + y * 57
>         n = (shiftR m 13) ^ m
>         j = (n * (n * n * 15731 + 789221) + 1376312589) .&. 0x7fffffff
>     in  1.0 - (fromIntegral j / 1073741824.0)
>
> the code compile but I get the same result for any input, due to the fact
> that n is evaluated to 0.
>
> Is there a better way to do that?
>
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