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Talk:OpenGLTutorial2

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Revision as of 23:02, 8 March 2011 by Emacstheviking (Talk | contribs)

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Excellent article and it got me going with OpenGL and Haskell but there is a small mistake that prevents the successful compilation at the point "3.1 Animation" in the revised Display.hs, function 'idle' ...

idle angle = do
  a <- get angle
  angle $=! a+0.1
  postRedisplay Nothing

To get it to work on Ubuntu with ghc 6.12.3 I had to change it by enclosing the update in parentheses like so,

idle angle = do
  a <- get angle
  angle $=! (a+0.1)
  postRedisplay Nothing

Hope that helps somebody else! EmacsTheViking