https://github.com/gelisam/glut-events

For writing GLUT's main loop in the style of Haskell's main function.
https://github.com/gelisam/glut-events

Last synced: 22 days ago
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For writing GLUT's main loop in the style of Haskell's main function.

• Host: GitHub
• URL: https://github.com/gelisam/glut-events
• Owner: gelisam
• Created: 2013-03-13T03:16:06.000Z (over 11 years ago)
• Default Branch: master
• Last Pushed: 2013-04-03T02:57:14.000Z (over 11 years ago)
• Last Synced: 2023-04-13T07:57:01.826Z (over 1 year ago)
• Language: Haskell
• Size: 168 KB
• Stars: 2
• Watchers: 3
• Forks: 1
• Open Issues: 3
• Metadata Files:
  • Readme: README.md

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README

        
glut-events

===========

For writing GLUT's main loop in the style of Haskell's main function.

(in development)

purpose

-------

Haskell's [Graphics.UI.GLUT](http://cvs.haskell.org/Hugs/pages/libraries/GLUT/Graphics-UI-GLUT.html) library exposes [GLUT](http://www.opengl.org/resources/libraries/glut/)'s approach to event handling: register global callbacks for the Keyboard, Mouse, Timer, Resizing, Redrawing, and Idle events. This encourages a style of development focussing on a shared global state, a style which is not typical in Haskell.

The purpose of this library will be to offer a Haskell-style wrapper around GLUT's platform-independent Input and Timing routines. In particular, much like Haskell's main method is typically written as an infinite tree of alternative IO sequences:

    main = do putStrLn "are you sure? (y/n)"

              s <- getLine

              case s of

                "y" -> putStrLn "full steam ahead!"

                "n" -> putStrLn "ok then."

                _ -> do putStrLn "please answer with 'y' or 'n'."

                        main

The goal is to allow you to write GLUT programs as an infinite tree of alternatives in some yet-to-be-determined monad:

    glutMessage = do clear [ColorBuffer]

                     renderString Helvetica18 "are you sure? (y/n)"

                     swapBuffers

    

    glut_main = do lift $ glutMessage "are you sure? (y/n)"

                   Char c <- getKeypress

                   case c of

                     'y' -> lift $ glutMessage "full steam ahead!"

                     'n' -> lift $ glutMessage "ok then."

                     _ -> do lift $ glutMessage "please answer with 'y' or 'n'."

                             waitForTimeout 1000

                             glut-main

long term goal

--------------

The above doesn't look to hard to implement. The hard part would be to allow waiting on multiple events (C-style select()), forking cooperative threads, sending events between threads, and releasing GLUT's idle callback when no threads are waiting for input. I still have no idea how to do this in a typesafe way, though, so don't hold your breath!