Graphics.UI.GLUT.Begin

After a GLUT program has done initial setup such as creating windows and menus, GLUT programs enter the GLUT event processing loop by calling mainLoop or handle events iteratively with mainLoopEvent.

Handling events

mainLoop :: MonadIO m => m ()

Enter the GLUT event processing loop; it will call as necessary any callbacks that have been registered. This routine should be called at most once in a GLUT program.

mainLoopEvent :: MonadIO m => m ()

(freeglut only) Process one iteration's worth of events in its event loop. This allows the application to control its own event loop and still use the GLUT package.

leaveMainLoop :: MonadIO m => m ()

(freeglut only) Stop the event loop. If actionOnWindowClose contains Exit, the application will exit; otherwise control will return to the function which called mainLoop.

If the application has two nested calls to mainLoop and calls leaveMainLoop, the behaviour is undefined. It may leave only the inner nested loop or it may leave both loops. If the reader has a strong preference for one behaviour over the other he should contact the freeglut Programming Consortium and ask for the code to be fixed.

Controlling the behaviour when windows are closed

data ActionOnWindowClose

The behaviour when the user closes a window.

Constructors

Exit

Exit the whole program when any window is closed or leaveMainLoop is called (default).

MainLoopReturns

Return from mainLoop when any window is closed.

ContinueExecution

Return from mainLoop after the last window is closed.

Instances

Eq ActionOnWindowClose

Methods

(==) :: ActionOnWindowClose -> ActionOnWindowClose -> Bool

(/=) :: ActionOnWindowClose -> ActionOnWindowClose -> Bool

Ord ActionOnWindowClose

Methods

compare :: ActionOnWindowClose -> ActionOnWindowClose -> Ordering

(<) :: ActionOnWindowClose -> ActionOnWindowClose -> Bool

(<=) :: ActionOnWindowClose -> ActionOnWindowClose -> Bool

(>) :: ActionOnWindowClose -> ActionOnWindowClose -> Bool

(>=) :: ActionOnWindowClose -> ActionOnWindowClose -> Bool

max :: ActionOnWindowClose -> ActionOnWindowClose -> ActionOnWindowClose

min :: ActionOnWindowClose -> ActionOnWindowClose -> ActionOnWindowClose

Show ActionOnWindowClose

Methods

showsPrec :: Int -> ActionOnWindowClose -> ShowS

show :: ActionOnWindowClose -> String

showList :: [ActionOnWindowClose] -> ShowS

actionOnWindowClose :: StateVar ActionOnWindowClose

(freeglut only) Controls the behaviour when the user closes a window.